That is allegedly a before and after picture of Jemma Barlas, a Canadian lesbian who was beaten up by a man named Matt Mutter after she slapped him for making fun of her for being a lesbian.
There a page somewhere that tries to make it seem like she was beaten up because she is a lesbian, but really, she was beaten up because she slapped a guy with an anger management problem.
The lesson here is don't slap people if they make fun of you, because you never know if the person you slap will flip out and beat the holy fucking shit out of you, even if you are a petite woman.
http://www.tigerdroppings.com/rant/p/34993298/Facebook-trend-of-the-day.aspx