Emma Chamberlain and I are in the bathroom after an excruciating SoulCycIe class in West Hollywood, which she attends every day, and because the 18-year-old YouTube star isn't wearing a top--just her SoulCycle-branded workout leggings and black sports bra--I have a mostly unobstructed view of her back.

As she leans into the sink to wash her face, she nods over her shoulder. "My bacne is out," Chamberlain says in a gust, the words careening out of her mouth. She doesn't say it self-consciously; it's more a statement of fact. Mid face wash, she reaches around and taps the breakout, almost in reverence. She dries her face with a towel, pulls her sweatdrenched hair out of her hair tie, and gives it a shake, piling it into a nest on top of her head. My face is beet red from the exertion, and I'll feel droplets of sweat rolling down my back for the next 20 minutes. It's the worst I've ever looked in front of a person I'm writing about, and yet I don't care. Chamberlain has that effect.

She has become one of the most popular new stars on the Internet by, essentially, talking about her bacne. She's unapologetically forthcoming about every aspect of herself, deeply skeptical, and self-deprecatingly honest. Her candor also covers, but is by no means limited to, her frequent burps and farts, her overly hairy legs, her diarrhea, the period blood dripping down her leg because she forgot a tampon. She broadcasts the minutiae of her life on YouTube, where she has over eight million subscribers. In her videos, she rarely wears makeup, and her hair is almost always tied up in a markedly unchic bun or high ponytail. For a generation that's grown up Altering photos and curating content, Chamberlain is a much-needed antidote to the pressure to be perfect.

It's clear she's tapped into something young women crave. Since launching her YouTube channel in June 2017, Chamberlain has gone from a depressed high school sophomore with little prior experience or platform to one of the most popular girls on the Internet, with the trappings to match. She graduated early from high school, relocated to Los Angeles from the Bay Area, and acquired an agent, a publicist, and partnerships with high-end brands like Louis Vuitton. In February, she was nominated for a Nickelodeon Kids' Choice Award for favorite social star, a high honor given that, according to a 2014 Variety survey, YouTubers are more popular among U.S. teens than mainstream celebrities. On top of her YouTube fanbase, she has nearly eight million Instagram followers and over two million Twitter followers. Her social-media engagement--the number of likes and comments on a post divided by her total number of followers--averages 25 percent on Instagram, where her photos regularly get between one and three million likes. (By comparison, Kim Kardashian averaged 4 percent engagement on five recent Instagram posts.)

Chamberlain and her generation are shaping our future. With her DGAF attitude and behind-the-curtain sensibility, she's started the...