Madeleine Holden has three simple tips for taking a good dick pic. First, zoom out. Second, clear the background of clutter. Third, experiment with angles. Then, for extra credit, consider tone, narrative, aesthetics and the desires of the recipient. “It was always those that elevated a dick pic from – to use my scale – a C- to an A+.”

As founder of Critique My Dick Pic, a popular Tumblr blog that ran for five years from 2013, Holden wrote thoughtful reviews of photographs of about 500 strangers’ genitals, from almost 10,000 submissions. (It was brought to an end in December last year by Tumblr’s ban on explicit visual content, a move widely decried as a blow to the diversity of sexual imagery online.)

Holden, a New Zealand-born lawyer and writer, had begun the project to counter the popular narrative around dick pics as nearly exclusively unsolicited and unwelcome, and to redeem them as “something that could have erotic potential”, she says. “I sort of felt like we had written off the possibility that the receiver could ever find them hot.”

Inspiration had struck when – after receiving “dozens, maybe hundreds” of unwanted dick pics from strangers, as happens to women on the internet – Holden finally received one from a partner that was actually good. Compared to the standard shot – a close-crop of the penis, often starkly illuminated by camera flash, that Holden came to term “the log” (hence her repeated refrain: “zoom out”) – “it was welcome and it was artful and I was thrilled to receive it”.

It revealed to her that, with dick pics, “there’s a way to do it that’s clunky and really not hot – and there’s a way to make it actually erotic”.

With the proliferation of “disappearing” picture messaging on Snapchat and Instagram and even an increasing number of dedicated secure platforms, sexting is becoming increasingly common, and not just for casual or one-off encounters. Dr Rob Weisskirch, professor of human development at California State University Monterey Bay, says his research shows that sexting is actually most common within a committed relationship: “It’s just a part of the behaviours, nowadays, in how we communicate with our romantic partners.”

There’s a way to do it that’s clunky and really not hot – and there’s a way to make it actually erotic Madeleine Holden

Yet even as it becomes more commonplace, the persistent framing of sexting is that straight men send images to women who did not ask for them, and straight women send images to men who ask for them. This is a myth, says Dr Michelle Drouin, a developmental psychologist and expert on technology and relationships. In fact, studies have shown them to record similarly diverse responses when asked about their sexting behaviours. “Men can sometimes feel uncomfortable sexting, just like women do. In terms of motivation, they often cite the same thing: fun, flirtation, laying the groundwork for sexual activity.”

Though there is increasing acceptance in this age of mainstream feminism and sex positivity that women desire sex as much as men do, the stereotype that “men are more visual” persists – even as other distinctions made on the basis of biological sex have begun to disintegrate.

A meta-analysis by Professor Jeff Temple of the University of Texas Medical Branch. showed that though men were more likely to ask for naked pictures, both genders sent them at about the same frequency. Though it may not be conscious, the intent might at least be partly reciprocity, he says: “I imagine some of it is, ‘We’re going to both be in this together – if I’m going to send something, I’m going to want something in return.’”

It is hard to separate any truth in the assumption that men are more responsive to visual stimulus than women due to decades of sexism that punished female sexuality, says Temple – though his suspicion is that it is mostly, if not entirely, a product of “old-school thinking”: “My guess is that women and girls get turned on just as much as guys get turned on from sexual imagery.”

Holden had initially intended for Critique My Dick Pic to interrogate this. But as her inbox filled up with submissions, she came to realise that the reality was far more diverse than she could have ever imagined. “I was getting pictures of women with dicks, hearing from men who loved to see dicks.” Trans people in particular told her how meaningful it was to see themselves represented in an erotic space.

She started to suspect that even straight men were not being well served by the assumption of them as undiscerning consumers: “Maybe they are more likely to see a picture of a vagina and think the same thing they say about pizza – ‘if it’s good, it’s good, and if it’s bad, it’s still pretty good’.”

It is as the sex educator and writer Emily Nagoski writes in her 2015 book Come As You Are: “Variety may be the only truly universal characteristic of human sexuality.” To the question “are men’s and women’s sexualities the same, or are they different?” she answers: “Yes.” They are “made of the same parts, organised differently” and, though there are some biological differences, “there is at least as much variability within those groups as there is between those groups”.

Women’s sexual response is more sensitive than men’s to context, characterised by Nagoski as external circumstances and present mental state. This is partly a result of biological difference, yes – but it is also learned. Nagoski writes that – without the “obligingly obvious physiological response” of an erection to link to external stimuli – what girls learn from a young age about what is “sexually relevant” is more influenced by social context than it is for boys.

Coupled with the enormous variation within women, this means, again, that attempting to separate differences between male and female sexuality from the bigger picture is fraught, if not futile. If women are more reticent to initiate sexting, suggests Toronto-based sex writer and podcast host Kate Sloan, it may be out of internalised shame or fear of judgment, or because of their own experience of being objectified.

Conversely, the importance of context for arousal may be a factor in many women’s preference for written erotica over pornography. “You can write very explicitly what the characters are feeling,” says Sloan. “It just flies in the face of the shitty cultural stereotype that consent ‘ruins the moment’, because it’s often a central facet of what makes these stories so sexy.”

If you’re a woman who’s into men, you actually don’t get to see a lot of the things you’re visually interested in Kate Sloan

If men do initiate the exchange of naked images more readily, says Sloan, they have been enabled to do so by a culture that predominantly tailors its imagery to the male gaze. “If you’re a woman who’s into men, you actually don’t get to see a lot of the things you’re visually interested in – you get to see a lot of what men think you’re going to be into.”

The dominance of that view can have lasting impact on what even straight women understand as attractive. When Sloan was a teenager, taking provocative, Suicide Girls-style pictures of herself – with a digital camera and tripod, as was necessary at the time – was “definitely a way of exploring the burgeoning idea that I might be sexy someday”.

Our tastes and desires are shaped by society, says Sloan, who is bisexual. She notes that even queer women not seeking to have sex with men may choose to present in such a “hyper-feminine” way as theoretically designed to impress them.

“In much the same way that you still have to make money if you disagree with capitalism, you still have to exist within patriarchy,” she says. “If part of that is that you’re only going to feel good if you have your red lipstick and high heels on, I don’t think there’s really anything wrong with that, as long as it is giving you genuine pleasure.

“I feel like you have to work with the boundaries you’ve been given, to a certain extent.”

Cultural norms are slowly changing, says Drouin, meaning some of our “more antiquated” ideas about differences between the sexes are being thrown out. “More women are embracing their sexuality and the culture is more accepting of that, certainly than 75 years ago.”

But for many women, sex remains inextricable from risk – of disease, pregnancy, violence – which inevitably affects their pursuit and enjoyment of it, regardless of the immediacy of the threat. This also applies to sexting, a “very, very risky endeavour” for both men and women, says Drouin: “These images can haunt you later on.”

Eva Bloom, a sex educator also in Toronto, says that though the taboo against sending naked images is slowly lifting, women are still being punished for it. Victims of revenge porn can sometimes suffer greater consequences than the person who illegally shared their pictures without consent.

But telling women not to sext because of the perceived risk denies them an “amazing opportunity for exploration”, says Bloom. Her recent study into sexting by young Canadian women found that those who did sext, even irregularly, were more likely to talk to their partners about safe sex, and what they liked and did not like in bed. Women who sexted frequently were more sexually satisfied, and more likely to report that their last sexual encounter was very pleasurable.

Though she has not yet established causation, Bloom suggests when there is trust, sexting can be a means of experimentation, and even vetting potential sexual partners. Sloan says that on her podcast The Dildorks, she and co-host Bex Caputo often advise that people float a fantasy with a partner over text first. “It feels lower pressure than being in bed with somebody and saying: ‘Hey, can we try this.’”

Sloan herself first dipped a toe into many of her own kinks this way. In general, she says, kinky and queer communities are more comfortable to approach sex as a highly individualised experience rather than assuming, “as so many straight, vanilla men do, that because you want to send a dick pic, it will be well-received”.

Holden says the best submissions she received for Critique My Dick Pic were those that were obviously concerned with pleasing the recipient, whether that was by displaying some “creative or artistic or erotic imagination” in the image or simply by clearing any piles of clothes from the background. “You have to think about ‘what would this person want to see?’

“There are generalisations you can make, there are even some gendered generalisations you can make – but, ultimately, sex is so individual and personal and touchy, at a certain point, you really do just have to say what you find hot.”