Charlie Knoles is a 39-year-old meditation coach and father based in California. He reads Politico, ProPublica and the Wall Street Journal, and posts on Facebook about all sorts, including science, technology and ethics. But recently he posted: “I now go to Teen Vogue for serious journalism.”

Not your average consumer of glossy magazines aimed at teenage girls, Knoles first found himself on the title’s website in December. “All my friends were talking about Donald Trump gaslighting America. I saw the links they were posting going to Teen Vogue. When I clicked through, I saw a fantastically well-reasoned piece of writing.”

The article in question was an impassioned op-ed by 25-year-old Lauren Duca, a Teen Vogue contributing editor and award-winning writer for the likes of Vice and the New Yorker. “To gaslight is to psychologically manipulate a person to the point where they question their own sanity, and that’s precisely what Trump is doing to this country,” Duca wrote, summing up with the rallying cry to: “Refuse to accept information simply because it is fed to you, and don’t be afraid to ask questions.” This is solid advice for any teen at any point in history; but in the era of “alternative facts”, it is also, she noted, “the base level of what is required of all Americans”.

The website has come to play a key role in repositioning the title as a voice for the resistance

Duca’s piece more than touched a nerve. With 1.3m hits and counting, it made an overnight sensation of its writer and marked what 29-year-old Teen Vogue editor Elaine Welteroth describes as a “watershed moment” in a gradual yet radical evolution of the title over the past 18 months. “I think that stirred up a larger conversation around how we think about young girls,” Welteroth says.

Launched in 2004 as a little sister to US Vogue, Teen Vogue used to focus on the standard cocktail of fashion must-haves and celebrity worship. (A classic coverline from a 2005 edition was How To Get Perfect Party Hair.) But beginning with the August 2015 issue, the team, including then beauty editor Welteroth, engineered a shift. That issue featured three unknown black models on the cover, seemingly breaking all the rules (that you should have a famous person; and that having no Caucasian faces on the cover is a commercial risk). “It was everything which, during my 15 years working in New York, I heard, ‘You can’t do it; it won’t sell,’” creative director Marie Suter told a reporter for the Atlantic. It became the bestselling issue of the year.

Facebook Twitter Pinterest Editors discuss ideas at their daily 11am meeting in New York. Photograph: Mike McGregor/The Guardian

On a bright and blustery Monday morning, I have come to meet the Teen Vogue team at their offices on the 29th floor of One World Trade Center in New York. The daily 11am editorial meeting is about to begin, led by 25-year-old digital director Phillip Picardi. Taller than he appears in his revolving gallery of Instagram stories, Picardi is dressed in slim-fit jeans and a navy shirt by Dries van Noten, his boyband looks dominated by luminous, aquamarine eyes. Last night he was up late into the night, tweeting about Lady Gaga’s Super Bowl performance and, at 10.15pm, writing a story for the site titled If You Think Lady Gaga’s Super Bowl Performance Wasn’t Political You Missed The Point. But if he’s fatigued, you’d never know it. He is poised and alert, with a side of excitable puppy.

This morning’s stories (the team publishes between 50 and 70 a day) present a typically mixed bag of fashion, entertainment and current affairs. Today’s hits are already at over 700k, with What Donald Trump Lied About This Week performing particularly well; there’s also a personal essay on the chemicals in hair relaxant, a roundup of Models Turning 19 Today, a story about Isis recruiting potential terrorists through social media, and an analysis of why Melania Trump chose to wear red for her first post-inauguration appearance.

Facebook Twitter Pinterest The new issue features actor Sasha Lane. Photograph: Amy Troost/Teen Vogue

“Why was it?” Picardi wants to know. “Because… she’s a republican?” the relevant editor deadpans, to peals of laughter. “Spoiler alert!” Picardi laughs.

It is the website that runs Teen Vogue’s most overt political coverage, and has come to play a key role in repositioning the title as a passionate and informed, if unexpected, voice for the resistance. Picardi was hired from fashion and wellness site Refinery29, where he was manning the beauty desk. When interviewed for his current job, he was asked: “‘How do you take the title from a two to a 10?’ My answer was, ‘We have to give her [the reader] more.’” he tells me. “I thought it was really important to talk about reproductive rights, gender. To dig into politics and the news cycle. Basically, by omission, we were kind of assuming that she’s not interested.”

At first, “that stuff was a very small dent in our traffic. We had to make the case that our audience would respond.” Sure enough, they did. And then some. “A year and a half later, give or take, traffic (to the site overall) is up over 200%. We finally hit the 10m [unique users a month] mark last month.”

Our sweet spot is 18- to 24-year-olds. Someone who is sophisticated, conscious

Picardi’s team watch the latest in the site’s Guys Read video series, in which young men read sexist comments made by real teachers to girls, to highlight the kind of casual yet systemic sexism that usually flies under the radar. The series, which last month saw them nominated for an American Society of Magazine Editors award (“like the Oscars of magazines,” I am told), was the brainchild of wellness editor Vera Papisova, one of Picardi’s hires and formerly a writer for Vice. “They’re all mine,” he tells me later, gazing affectionately at his staff from his office. “My deputy editor comes from Yahoo Health, our social media director from Gawker. Changing the editorial direction meant diversifying the backgrounds of the people in our newsroom.

Facebook Twitter Pinterest Phillip Picardi: ‘Changing the editorial direction meant diversifying the backgrounds of the people in our newsroom.’ Photograph: Mike McGregor for the Guardian

A posse of snappily dressed millennials, the team is also a reflection of the title’s demographic, which “ages up”, in the words of Welteroth; in other words, they’re not all teens. “Our sweet spot is 18-24,” she tells me. Also describing her readership as “genderless”, she explains that “it’s more about a sensibility. This is somebody who is sophisticated, conscious. We say ‘woke’ here. We’re a woke brand, and our readers are woke, too.”

The Merriam-Webster dictionary describes the word “woke”, a slang term, as “a byword for social awareness.” (See toddlers attending the Women’s March on Washington in T-shirts bearing slogans such as “Ready for a nap but born woke”.) It could also be applied to Condé Nast director (and US Vogue editor) Anna Wintour’s decision to hand the reins to Welteroth, with the remit to “Keep doing what you’re doing.”

Welteroth, who was made editor of the monthly print edition in May 2016, and is only the second African American editor of any Condé Nast title in its 108-year history, is widely credited as the driving force behind the magazine’s shift. We sit down in her glass-walled office to look at proofs of the new edition. The room is filled with the usual glossy magazine editor’s paraphernalia: her desk is scattered with beauty products and invites to fashion shows; her supersized iPhone buzzes with news updates. But her manner is a million miles from the “old media” Devil Wears Prada stereotype. Dressed in a dogtooth Altuzarra suit, a pair of wire-framed specs perched on her nose, Welteroth exudes a warm and approachable “big sister” vibe.

She is also as media-genic as Picardi, with close to 90k followers on Instagram, where she posts a mixture of selfies with the actors and models she champions, pictures of Beyoncé (sample caption “Pardon me while I bow down”), and near-daily updates from spin classes and facials. Last year, she had a cameo playing herself on cult sitcom Black-ish, while her recent engagement to her childhood sweetheart, singer-songwriter Jonathan Singletary, led to a joint interview on ultra-hip fashion blog Man Repeller.

Facebook Twitter Pinterest Editor Elaine Welteroth: ‘We’re a woke brand, and our readers are woke, too.’ Photograph: Mike McGregor for the Guardian

Since Welteroth joined Teen Vogue, covers have consistently featured women of colour, while inside there are stories on cultural appropriation and the new faces of feminism. Creative director Marie Suter is charged with keeping the look and feel “elevated and sophisticated, no matter (how radical) the content”, and the web platform operates as “a playground to test out different things” – what Welteroth calls “consumer research on demand”.

Condé Nast closed the print edition of another magazine, Self, in December 2016, and there are ongoing editorial layoffs company-wide: why keep the print edition at all? “It’s something I hear all the time, but not as much from teens,” Welteroth says. “What I find is that when young people find a brand they relate to, that they feel speaks to them, they want it in every format they can get.”

From this week, Teen Vogue will have a new format, relaunching as a quarterly “journal”, with a new slim shape the same dimensions as an iPhone, only bigger (“the iPhone is this generation’s third arm,” Welteroth explains). The first issue has three collectable covers, featuring indie cinema darling Sasha Lane (star of Andrea Arnold’s American Honey), a candid shot of model Bella Hadid in the bath, and YouTuber turned actor and musician Troye Sivan, the latter shot by arthouse photographer Ryan McGinley.

Sivan recently talked about being gay in a YouTube video, and is interviewed for the magazine by his friend, the transgender model and actress Hari Nef. “They talk about the role the internet plays in coming out of the closet, and finding your community as a queer kid in 2017. It’s really heart-touching, and honest,” Welteroth says. The redesign was announced in November last year and print subscriptions instantly spiked.

“But we would do it anyway,” Welteroth says when I point out how it must help that opinionated political reporting also turns out to be lucrative. Does she consider herself an activist as much as an editor? She flicks through the magazines in front of her to find a quote from the December issue. “I learn a lot from the girls we feature, and [star of Disney show Girl Meets World] Rowan Blanchard wrote how ‘Activism is a need to know, a need to explain, and a need to help.’ So, by this definition, I am an activist. And I think the readers that we reach would all consider themselves activists, too.”

Facebook Twitter Pinterest One of the new covers features YouTuber Troye Sivan. Photograph: Ryan McGinley/Teen Vogue

What issues are most important to their young readers? “Identity is big. We want to help make them feel better about themselves, whether that’s giving beauty tips, or empowering them with political information to have smarter conversations and feel they can stand up for themselves.” Career advice “is an evergreen topic”; above all, “young people are craving something real, craving authenticity”.

Hailing from the San Francisco Bay Area, Welteroth studied media at California State University before moving to New York to work as a beauty editor on Glamour magazine. As a child, “my mom used to call me ‘Oprah’ because I was always in a corner crying with somebody,” she says. “I’ve always been attracted to storytelling around women’s lives.” Meanwhile, her ambition for Teen Vogue is “to highlight underrepresented voices and role models, and to create a magazine that didn’t exist for me growing up. I mean,” she leans across her desk, “when I was 14, I did not know what intersectional feminism was.”

Putting Hunger Games actress Amandla Stenberg on the February 2016 cover was a turning point. “She’s a brown girl who had a big afro, which one could say is progressive for a Condé Nast title.” And, unusually for a cover star, Stenberg didn’t have a major Hollywood movie to promote. “But she basically schooled the world on what cultural appropriation is,” Welteroth says. Stenberg has had more than 2m views for a YouTube video titled Don’t Cash Crop On My Cornrows, in which she analyses how African American hair, dance moves and music have been appropriated by white artists, who then fail to speak out about police brutality against men of colour. “It was smart. It was badass. And it was not finger-waggy. To me, she emerged in that moment as a voice for her generation,” Welteroth says.

There were several years when Teen Vogue was seen to embody the most bland type of media aimed at young girls; commercial, safe, focused on shopping and body image. As part of a backlash of sorts, the writer and editor Tavi Gevinson set up Rookie magazine in 2011, when she was 15, a website that was explicitly feminist and complex. “The biggest headline on an issue of Teen Vogue I bought when I was 14 was Your Best Body,” Gevinson tells me. “Now they’ve successfully rebranded themselves to appear in opposition to toxic ideas and beauty standards.” Last year, Gevinson became a cover star of the new-look Teen Vogue. She believes the internet has created an “accountability culture”, where the relationship with readers is closer and more transparent, and says brands have had to respond to that. “It is in their best interest to subvert expectations of teen girl magazines,” Gevinson says. “The general response to Teen Vogue’s shift seems to be shock and praise, because they are a Condé publication whose main concern is making money. And being political and feminist are considered risky, PR-wise.”

This approach to teens is not new, argues Mikki Halpin, author of It’s Your World – If You Don’t Like It, Change It: Activism For Teenagers. It’s just that it’s being taken seriously now. “If anything is new, it’s that mainstream media is no longer writing off journalism and opinion pieces aimed at young women,” she says. Halpin is editor-at-large of Lena Dunham’s Lenny Letter and creator of grassroots activism newsletter Action Now; she worked with Welteroth at US Glamour magazine, and was Picardi’s boss at Refinery29.

Facebook Twitter Pinterest The fashion rail in the Teen Vogue office. Photograph: Mike McGregor/The Guardian

Picardi credits Halpin with his own political awakening. “Mikki has this effect on people where you realise there’s a lot of work to be done,” he tells me. Growing up gay in a staunchly Catholic family in Boston meant that “I can certainly relate to what it feels like to be underrepresented or even marginalised. I took sex ed classes and there was no mention of homosexuality. Or I would sit in religion class and be told my life was a sin.”

Coming in the wake of a summer of social and political unrest, Trump’s election created something of a perfect storm for Picardi’s new political agenda; the Teen Vogue news desk had already caused a stir with strong coverage of the Dakota Access pipeline protests and the Black Lives Matter movement. Instead of merely reporting them, Picardi says, they try to figure out what their readers will care about the most, and this often means finding the personal interest angle. One of the first stories Picardi went big on was the case of Freddie Gray, a 25-year-old black man who died of spinal injuries following a brief (unwarranted) stint in police custody. “Black male teens are 21 times as likely to be killed by police than their white counterparts – 21 times. Can you imagine that?” ran the opening paragraph. “Think about your brothers, cousins, fathers – can you imagine hearing that number and seeing their faces in your head?”

There were several years when Teen Vogue was seen to embody the most bland type of media aimed at young girls

Do Teen Vogue’s readers see themselves the same way the editors do? I talked to 16-year-old Paige Wagner, who says truthfulness and trust are the main reasons she reads it, since “most of what I read on social media is unreliable”. For her, “The recent presidential election brought to the surface a lot of important issues that weren’t getting as much attention as they should have: women’s rights, LGBTQ community rights, immigration.” Like many young people, Wagner is galvanised by the election, in which she saw “a complete misrepresentation of the younger generation. It’s important now to educate young minds so they can form a political identity. We are the future of America.”

Does she see a conflict between the glossy glamour of a Condé Nast publication and political reporting? No, she says: it’s “brilliant” that she might see fashion advertising on the same page as a story on the environment. “I think it’s OK to be interested in both.” One of her favourite recent articles on teenvogue.com was Netflix Stars Open Up About Representation And Strong Female Leads, a piece in which actors from Orange Is The New Black and Dear White People discuss breaking stereotypes on screen. As evidence of the mix, last year’s top story after Duca’s gaslighting piece was titled, non-ironically, How To Apply Glitter Nail Polish The Right Way.

What sells magazines? Ask Peppa Pig Read more

Meanwhile, Duca has been given a political column in the new print edition and is, Welteroth says, kicking off with a story on “how to talk to people you love, but disagree with deeply, politically. And couldn’t we all just take a crash course on that?”

She and Picardi were at the Women’s March in January, she tells me, along with members of the team. “And people at different marches were sending me pictures of banners talking about Teen Vogue,” Welteroth says. She shows me a favourite that simply reads: Teen Vogue Will Save Us All! “I always say it,” she continues, “I honestly think our readers are gonna save the world.”