If you frequented Vine at all, you probably saw the video at least a handful of times. Brittany looks at her small Weiner dog and opens her mouth in a mock scream, to which her dog sticks his snout in her mouth.
The video was comedic gold while Vine was popular, and Brittany's following on the app rapidly grew.
But at the height of her career, she decided it was time to leave.
Why did Brittany leave Vine when her career was just getting started? She's featured on a new episode of E! True Hollywood Story where she reveals her decision to leave.
Why did Brittany Furlan leave Vine? She said it was "toxic" for her.
In a clip from the new episode, Brittany details what it was like to be the most-watched female Viner.
"For sure, Vine changed my whole life," Brittany said.
"My phone was ringing off the hook," she details. "I had all these opportunities."
At the time, Brittany was listed as one of TIME magazine's 30 Most Influential People on the Internet. But before she was a Vine star, she describes herself as "really shy."
"I was like, the little kid that hid behind their mother or their father's leg," she said.
But making Vines changed her into a person she didn't recognize. "I don't know what happened — I just became this monster who constantly wanted to perform," she said. But after her peak, her numbers began to dwindle.
"I left Vine because Vine got more toxic for me than it did positive," she said about her plateau in followers. It was then that she made the decision to leave the app, before its eventual end in 2015.
But even on Instagram, she still struggles with her expectations for internet fame.
Even though her ultimate decision to leave Vine was to hopefully find a better environment, she says that she still struggles with the expectations she set for herself.
"I take everything really personally. When I was on Vine I had 10 million followers, OK?" she said. "Now I'm on Instagram and I have 2.6 million."
While many other Vine stars made their jump to YouTube, Brittany made the decision to switch to Instagram and Facebook, looking for a warmer community than she found on Vine.
"You start to think, 'Well, what was I doing better when I had all these other followers on this platform that I don't have them all on this one?'" Brittany said.
According to a doctor in the clip, fame can get the better of these influencers, becoming the only thing that they can focus on — like an addiction.
"It's actually really sad because I depend on the approval of others in order to be successful in my life," she said. "Which is really depressing."
You can watch the new episode of E! True Hollywood Story Sunday at 10 p.m. on E!