It was a 30-degree December day, but to the 25 bystanders shoving their iPhones 3 inches away from Jen Selter’s butt, it was hot hot hot. Selter, a 20-year-old Instagram star, famed for her large derriere, was demonstrating her squatting technique for the New York Post atop a subway rail in Midtown, clad in nothing more than a sports bra and hotpink yoga pants.

Photos: Jen Selter is best known for her “butt” which has over one million instagram followers. Her one leg on the ground, one leg extended to the back has become known as “seltering” and is a current internet meme. (Photos By Zandy Mangold)