The best thing to do is go to ch131.com or surfthechannel and watch the episode you missed. IN fact, being in the US, I think you could watch it on the Fox website.
If you really want to know...read on.
Lauren did some digging and found out that Quinn used to be a chubby brunette named Lucy who had a different nose. She then put posters with photographic evidence all over the school. And later apologised. I didn't think it was any meaner than Quinn's own Glist last season so it could be argued that she had it coming...
Brittany mean Lesbian.
The kids all had something they didn't like about themselves, or had struggled with, put onto their shirts to show that they loved themselves and were 'born this way'.