Mimicry in nature was first observed in butterflies, in the 19th century. Certain breeds pose as wasps; others bear marks falsely advertising that they are poisonous. Desire for survival alone couldn’t account for the freakishness of camouflage. The novelist Vladimir Nabokov reported on butterflies so creatively exuberant that when masquerading as leaves, they imitated the small holes chewed by grubs. What predator could appreciate such subtlety? These were “nonutilitarian delights” — this was art, he said — nature playing “a game of intricate enchantment and deception.”

The French philosopher Roger Caillois took a darker view. “Why do sole and turbot borrow the colors and even the contours of the sea-bottom?” he asked. “Out of self-protection? No, out of self-disgust.”

For 40 years, Cindy Sherman, the great chameleon of our time, has created more than 500 photographs and almost as many distinct characters. She has transformed herself into vamps and victims, biker chicks and slasher babes, lonely-hearts and killer clowns. She has made herself over to look like a Goya painting and a lactating Madonna; a society matron with pink-rimmed eyes, radiant with contempt; an ashen-faced corpse, the lividity just setting in. John Waters has called her a “female female impersonator.” She has put it more simply, joking, “I collect breasts,” referring to the prosthetics she uses in her work.

Her first series, the landmark “Untitled Film Stills,” 1977-80, featured 70 black-and-white photographs of scenes from fictional films, inspired by Hitchcock and Antonioni. She developed some in too-hot chemicals to give them the cracked, grainy look of cheap promotional materials. The camera stalks the women, all played by Sherman, as they stand in dark alleys or wait to hitch a ride on a lonely road. We glimpse them through bathroom doors left ajar, absorbed in their mirrors. Each photograph could be captioned: The last time she was seen alive.

Other series followed, each an investigation into a female type and its iconography. She posed as fairy-tale characters, Botoxed grandes dames, aging film stars. An image from her 1981 “Centerfolds” series — of a young woman with bobbed hair and flushed cheeks lying on the floor, clutching a crumpled personals ad — sold at auction for nearly $3.9 million in 2011, the most paid for a single photograph at the time.

Her work is so defining that “you can’t make a photograph without the entire history of Cindy Sherman’s oeuvre behind it,” the artist Marilyn Minter has said. In fact, her images are so foundational to feminist art criticism, to notions of the “male gaze,” that it can be difficult to see them for themselves — they come to us encrusted with theory. Sherman herself is reluctant to discuss the meaning of her work; she is amused by the interpretive frenzy it provokes. “The fact of her silence is now almost part of Cindy’s canon,” the curator Darsie Alexander said at the opening of a 2012 retrospective.

But Sherman is vocal, even prickly, about one point. The photographs are not self-portraits, nor do they depict her fantasies. She uses herself because it’s simpler, she says. She can push herself harder than any model, and she can avoid small talk. Starting in 1985, she briefly disappeared from her own artwork. The “Sex Pictures” series, 1989-92, featured a kaleidoscopic combination of mannequin limbs, orifices extruding tampons and sausage links (“the unsexiest sex pictures ever made,” Jerry Saltz wrote in New York Magazine).

Posted on May 12, 2017. Artwork by Cindy Sherman Posted on May 25, 2017. Artwork by Cindy Sherman Posted on June 14, 2017. Artwork by Cindy Sherman

Posted on Aug. 4, 2017. Artwork by Cindy Sherman Posted on Nov. 1, 2017. Artwork by Cindy Sherman Posted on Jan. 22, 2018. Artwork by Cindy Sherman

Posted on May 11, 2018. Artwork by Cindy Sherman Posted on Jun. 27, 2018. Artwork by Cindy Sherman Previously unpublished. Artwork by Cindy Sherman

Despite loathing selfies (“so vulgar”), Sherman has recently taken to Instagram, where she has been producing a series of images utterly unlike anything she has created. Her photographs have always had a strong narrative, an ability to suggest an entire psychology or story line in a single detail — the way a woman hesitates in a doorway, as in a portrait from “Untitled Film Stills,” wearing white stockings and dark glasses, barely hanging onto her martini glass and staring at the viewer with alarm. But with the Instagram series, Sherman isn’t riffing on recognizable archetypes. Her new mock self-portraits are of ordinary people, albeit cartoonishly caricatured. They are some of the first pure protagonists in Sherman’s work: These women are not metaphors, they are not waiting to be represented, rescued or destroyed. They are gloriously, catastrophically themselves, and we meet them on their own terms — as we so frequently meet each other — in stagy, embarrassing, endearing selfies launched into the world.

Sherman, who is 64, lives and works on two floors of an apartment in SoHo overlooking the Hudson. After a number of high-profile relationships — with the Talking Heads frontman David Byrne, the artist Richard Prince and a 16-year marriage to the filmmaker Michel Auder that was haunted by his heroin use — she is now single, “except for my bird,” a 28-year-old macaw named Mr. Frieda, a superb mimic in his own right. He and Sherman share the same laugh.

I visited Sherman’s studio this summer, a wonderland of wigs, costumes and doll parts, the walls papered with the covers of old gore magazines and pictures of classic vamps. We talked at a low wooden table encircled by a dozen faceless mannequin heads. Between us lay a twisted piece of pantyhose, fake knuckle tattoos and a patch of crispy looking hair — a merkin? “I thought so, too,” she said, visibly disappointed. “A beard, and it’s real cheap.”

Previously unpublished. Artwork by Cindy Sherman

Sherman is a creature of inveterate disguise. She was born Cynthia but still goes by her childhood nickname, Cindy, which, with its guileless, girlish all-American feel, suits her better. “The nicest girl on any block,” Calvin Tomkins wrote of her in a 2000 New Yorker profile. (Sherman was 46 at the time.) Betty from “Archie,” all grown up, is what I thought, fresh-faced and friendly, sandy hair pulled back in a ponytail, fluffy bangs — even more camouflage. Sherman used to box for exercise — “fast and aggressive” a former trainer described her in an interview for the Tate. “A pit-bull terrier,” said a sparring partner. Mild and obliging in person (in an interview, she mentioned working in therapy on being less accommodating), the ferocity goes into the work. Exasperated by the inflated art market and prices commanded by “boy painters” — Schnabel, Salle — in the 1980s, she made a lurid series of photographs of slime, blood and bodily fluids. “Hang this vomit above your couch,” she said at the time. The X-rated “sex pictures” featuring mannequins were, in part, a furious challenge to the censorship battles of the early ’90s.

This split in her is pronounced and goes back to childhood. Sherman was born in 1954 in Glen Ridge, N.J., and raised on Long Island, the last of five children. Her closest sibling in age was nine years older, and Sherman grew up feeling like an intruder. “It wasn’t that they didn’t like me, but I came along so late and they already had a family,” she told The Guardian in 2011. She started dressing up to woo them. “I felt like this straggler that was running after them, saying: ‘Hey, remember me?’ ” she said in a later interview. “ ‘Don’t forget about me!’ It was easy to erase myself and put on somebody else’s face and say, ‘Maybe now you guys will remember me,’ or ‘How about this face or that character?’ ” But sometimes it was safer to be forgotten. Sherman’s father was a racist and a “creep,” well into his final years, when he took to tormenting fellow nursing-home residents.

Posted on Jun. 4, 2018. Artwork by Cindy Sherman

Sherman studied art at SUNY Buffalo State, where she failed her introductory course in photography. But she became interested in how Eleanor Antin, Adrian Piper and others were using role-playing in their work and fell in with a group of artists, including Robert Longo, who became her boyfriend. She and Longo moved to New York in 1977, the Summer of Sam. Sherman found the city terrifying. “I was really shocked at how I was treated just walking down the street,” she recalled in a 1994 documentary. She wore men’s clothes when she left the apartment, when she managed to leave at all. Longo remembered her getting made up and being too frightened to go out. She would hide in her room and play dress-up, and she began taking photographs of the characters she was creating. She and Longo would drive around New York, shooting some photographs for what would become “Untitled Film Stills” on the West Side piers and around the World Trade Center. Sherman would change clothes and get into character, crouched in the van.

She has worked alone since then, with her camera and mirror and prosthetics. “Nobody’s here but me,” she says, in the documentary of that name. We see glimpses of her at work — trying on costumes in front of a mirror, dancing a bit. She sits on the floor and fusses with a male medical mannequin. “He’s got a nice face,” she says; then, in a low, happy voice, “and his teeth come out.”

Posted on Nov. 9, 2017. Artwork by Cindy Sherman

For years, Sherman and Auder lived out of the spotlight. When the marriage ended, she shook off seclusion. She began attending more art openings and fashion week. She moved part time to the Hamptons. Her first Instagram posts were of her new home — the hot pink sunsets and chickens scratching in the dirt (“my girls”) — and her new, more public, casually fabulous life. There she is, posing with Isabelle Huppert and Catherine Deneuve, accepting the Praemium Imperiale award in Tokyo along with Martin Scorsese, taking her biannual trips to a Bavarian spa. But in its celebrity-studded way, her Instagram feed was homey too. Molly Ringwald popped up in the comments of a garden photograph, curious about espaliered trees.

Only while recovering from a fall off a horse in 2017 did she begin “fooling around” with the new photographs in earnest. A hair colorist introduced her to a makeup app that could “erase” blemishes, smooth away wrinkles and whiten teeth in photographs. Sherman put them to typically perverse uses, churning out tricked-out selfies, with her neck elongated like Alice in Wonderland and big bug eyes, epic sun damage and elaborately pleated wrinkles.

Ingrid Sischy, who commissioned what became Sherman’s 1981 centerfold series for Artforum when she was the magazine’s editor (and decided not to run them for fear of a backlash), once said that Sherman’s work resonates so much with viewers because she involves them: “It’s really this kind of contract with Cindy and the viewer, that the viewer will suspend disbelief and go with her.”

A new contract needs to be written for her recent work, however. We come to it for the disbelief, to marvel at how a face can be so manipulated and somehow still be legible, even familiar. In one image, a woman’s face floats above a mountainscape. She looks like a Barbie doll left out in the sun; her skin is tightly stretched. Her gaze hovers complacently in the distance. She smiles broadly. Her lips are cracked and dry and slightly misshapen — maybe fillers gone wrong? Liver spots speckle her forehead and cheeks. “Traveling really takes it’s toll,” reads the caption. I laughed when I first saw the picture. She is wonderful, this woman: striking and odd, indefatigably optimistic-looking. But then she uncorks something different in me, a kind of protectiveness. She has no camouflage. None of the women in the series do. Their vulnerability pains me — how badly they want to achieve some kind of glamour, how magnificently they miss the mark. A face “just floats there in front of you,” Marilynne Robinson once wrote. “It might as well be your soul, for all you can do to protect it.”

Posted on Feb. 6, 2018. Artwork by Cindy Sherman

Short stories unspool in the comments, little dramas. On a photo of a slim woman with short hair and narrow, slightly saurian eyes: “The fitness-obsessed middle manager who thinks about stealing the hotel robe but doesn’t?” someone guesses. Another: “R U my sister in law?” The images elicit visceral responses of recognition. On a photo of an older woman in a fortuneteller’s get-up, with heavy eyeliner and a septum ring, the comments read, “I can smell her perfume,” “Imagine getting stuck in the lift with this one.” Viva Hoffman, one of Andy Warhol’s Factory superstars who was also married to Sherman’s ex-husband, Auder, marvels at the character: “I met her in her studio all done up with the eyelashes and the beads and the turban. She was scary. I was 22.” Commenters root for the women: “I’m fixated on the thin eyebrow ... in a world of picture perfect perfection she’s given up. This is her subtle rebellion.”

These are all photographs of subtle rebellions — the first being the demand, of women of a certain age, to be noticed, admired. Or do I have it backward? The longer I look at these photographs, the less sure I am of them. Are these women insisting on being seen or are they taunting us, mischievously playing on fears of female ugliness, of becoming old and absurd or just invisible? That slipperiness in her work — does she see people clearly out of kinship or cruelty? — becomes complicated here by her ambivalence about aging. On one hand, she expresses solidarity with the classicist Mary Beard, who has pushed back at criticism of her appearance: “That is what 59-year-old women who have not had work done look like. Get it?” On the other, Sherman still bemoans getting older, the way “everything falls apart at 60.” But she told me, “I can tape my neck for the photos.”

I asked her if she has models for aging rebelliously. She lit up. Michèle Lamy, she told me, an improbable choice, you would think, for Sherman, so sunny and physically unobtrusive. Lamy is the well-known 70-something fashion muse and wife of the designer Rick Owens, who wears elaborate Gothic creations and dyes her teeth and fingers black with vegetable dye. Sherman pulled out her phone to show me a few pictures. She tried unlocking it using facial recognition, but it wouldn’t work. She lifted and lowered her chin, then raised her eyebrows. The studio was wrapped in a velvety silence broken only by the sound of Mr. Frieda muttering to himself across the hall. She opened her eyes wide and held the phone very still. She was trying to look like herself.