The Miu Miu skirt is so short that it seems to have no end. For the last two weeks, it has made nearly daily appearances: on the covers of magazines, on the bodies of celebrities and influencers, and as the subject of articles about its reach.The styling is part of that reach. Usually the low-rise miniskirt is worn with an equally extreme crop top, a polarizing look that receives extra attention whenever it’s worn by someone who does not resemble the models who introduced it on the Miu Miu runway in October. Like a 50-something actress or a plus-size model.But on Tuesday, the skirt made it clear — because the skirt is now sentient, with its own Instagram account and everything — that it’s not going anywhere.At Miu Miu’s fall 2022 runway show, new ultrashort variants were born: not raw-edged khaki and gray, like the slashed school uniforms introduced in the spring 2022 collection, but pleated white tennis skirts and dark leather boy shorts.At least 10 of the original skirts were in attendance to witness their evolution. Arriving at their seats, the women wearing them looked down at the sloping deck chairs lining the runway, contemplating how to best sit down.“Before the show, they asked me which looks I’d be interested in, and I thought there’s no way that they’d send me this look,” said Jenny Walton (336,000 followers), a fashion illustrator who expected the skirt would be in demand. (When highly photographed people are invited to fashion shows, they are typically dressed by the brand in pieces currently sold in stores.)After learning she’d secured the look, Ms. Walton scheduled workouts at Barry’s Bootcamp in Paris for the next three days to prepare. Trying it on for the first time, she thought the length was “crazy,” she said. “But the underwear holds it in place.”The beige underwear was part of the look; its top band was meant to peek out from the waist of the skirt, adding about an inch to the overall look. (Think Tommy Hilfiger boxers in the 1990s.) Ms. Walton, standing in the middle of her row, gamely flipped one end of the skirt up to display the sturdiness of the fabric.“I mean, I already have this much of me exposed,” she said, gesturing at the expanse between the bottom of her breasts and top of her hip bones.Xenia Adonts (two million followers), an influencer and founder of Attire the Studio, said she wore her own underwear underneath the skirt. She called the look “surprisingly easy to wear” but felt it “could be a bit longer in the back.”“I was asking my boyfriend, ‘Can you see my butt?’” she said. “And he’s, like, ‘No.’”When asked if they felt at all overexposed, the women said no.“It’s sexy, but not too sexy,” said Ginevra Mavilla (538,000 followers), who wore the skirt with almost knee-high socks and pointy-toe, kitten-heel loafers. “It values the woman’s body, and it gives you a lot of confidence.”It also made her feel a little nostalgic.“It’s like a revival of high school,” said Ms. Mavilla, who is 19.