Inside Edition rode along with her as she showed Correspondent Diane McInerney how to strike a pose.
"I saw the right time to take a photo and I was like, 'I'm just going to do it,'" George told Inside Edition of the viral moment.
Initially, she explained, she had an empty subway car. But even when people got on, she kept going.
A passenger recorded her as she struck pose after pose, and the straphanger posted the video on Twitter, where it's been viewed more than 9 million times, with many praising her for her confidence. Virtually overnight, George went from just 200 followers on the platform to more than 30,000.
"I really had no idea that anybody was recording me," she said.
And it's not as easy as it looks. McInerney lost her balance trying to replicate George's poses.
"It's a lot of work getting that perfect selfie," said McInerney.
Check out the video above for George's tips.