I wouldn't have been offended. You have no idea what I actually look like, and the topic is already on my wieght. The Facebook commenter made it (I assume) based on my profile picture (which up until then I had thought was quite flattering), so it felt personal (not a generic fat joke). It also came out of nowhere, the topic I had commented on had nothing to do with weight. It caught me off guard, as there was no reason for the comment other than to be a judgemental bitch. People weren't even that rude and petty in high school (and I've always been fat).