When 16-year-old Riley Galfi met an artist she loves at a concert back in May, she didn’t ask to take any ordinary selfie with him, she asked to take a .5 selfie.

In a flash, Galfi flipped her phone around, angled it above her head and pressed the volume button to capture a fun, wide-angled picture. As she recounted the experience to CNBC, Galfi was beaming.

“I took a .5 with Aidan Bissett,” she said. “What? That’s really cool.”

The wide-angled image is colloquially called a .5 selfie, called a “point five” by Galfi and her peers. The cheeky photo trend has taken social media platforms by storm. 

The .5 selfie rose to prominence after Apple first introduced an Ultra Wide camera lens to its iPhone 11 product line. The style is particularly popular with members of Generation Z, or people born after 1997, according to the Pew Research Center. 

Gen Z has already witnessed the rise of smartphones, social media, and more recently, artificial intelligence, in their lifetimes, so these savvy users are accustomed to keeping up with ever-changing technology trends. 

On platforms like Instagram, for instance, Gen Z users don’t favor a perfectly curated feed full of posed and filtered photos. Instead, many are embracing a seemingly more effortless, messy, I-did-not-have-to-try-very-hard-to-capture-this-cool-outfit aesthetic. 

Enter the .5 selfie. 

“They’re not like the usual selfie, they shouldn’t be a well thought out picture that you take,” 24-year-old Rachel Aquino told CNBC in an interview. “It’s something that you just usually take on a whim, and something that really captures the moment in real time.” 

Aquino has taken a .5 photo every day for the past year. She said she uses them as an easy form of personal record keeping to capture her everyday life, her outfits, events and moments with family. 

She also likes to take .5 selfies when hanging out with friends, and she joked that if she doesn’t reach to take one, someone else will. Aquino said it usually takes her just two or three times to nail the shot since she isn’t striving for perfection. 

“Sometimes, I don’t look at the camera, sometimes, it’s literally the back of my head and me walking in the streets of New York, sometimes, it’s me sitting at a table with friends,” she said. “Sometimes, if I’m having a really good time and I don’t want to bother anyone, it’s like the back of everyone’s heads.”

At her job, Aquino is known as “the .5 queen,” and she said she often shares the photos to her Instagram and TikTok accounts. 

The .5 selfie is now a fixture of Instagram Stories and a popular Gen Z Instagram trend called a “photo dump,” where users share a group of up to 10 random, nonchronological photos to their main feed. Spliced between gorgeous landscapes and fancy meals, a .5 selfie can serve as a way for Gen Z to show off their personalities on the platform. 

Gabriel Lesser, a 21-year-old college student, said lots of his friends share their .5 photos on Instagram, and that they “always make the cut” in a photo dump. He said he has one friend who abides by the slogan “make Instagram casual again,” so she mainly posts .5 photos.     

“I think it just creates less of an expectation for the photo,” Lesser told CNBC in an interview. “You get some cool angles and funny, goofy proportions and you’re like, ‘This is hilarious.'”

For many professional social media creators, the more casual online aesthetic has proved to be a lucrative one. Popular Gen Z creators like Alix Earle and Emma Chamberlain, who has more than 15.7 million Instagram followers, have built brands around their relatability. 

Chamberlain’s photos are edgy, fun and not totally polished, which means they could theoretically be recreated by anyone. Her more attainable vibe has helped her reach some less attainable early career milestones like inking a podcasting deal with Spotify, starting her own coffee company and traveling the world with brands like Louis Vuitton. 

Some creators have also gotten their start purely thanks to the .5 lens.

Internet users have become enamored with Sabrina Bahsoon, a creator on TikTok who is more affectionately known as “Tube Girl.” Bahsoon blew up on the video-sharing platform this year because of the .5 videos she films while taking public transit in London. Her videos ooze confidence and style, and they landed her a spot at a number of designer fashion shows this fall.

“Just to see someone out there recording and so confident and looking so good at the same time is crazy,” Aquino said. “I think that’s why Gen Z goes insane over the Tube Girl.”