This is anti bullying day, and by posting this you are encouraging people to go and make fun of her. The comments are horrible, lots of people just insulting her for no reason. What do people gain from making fun of her like this? There are certain people who post things for attention, trolling us, and they can take it. This girl is probably not one of them.
As Zmoney said, Hope that poor girl doesn't hurt herself or something. The video appears to already have been viral for a long time, so hopefully the girl is doing fine and moved past this. I think the video was pretty good to be honest. I make silly videos sometimes and post them on YouTube and later regret it, but lose the password/email to the account so I can't remove it.