I made up my own little scenario from the photos, I'm usually wrong to be fair though. I thought Blair was obviously in disguise going back to school because she was embarassed and then Serena convinces her to take off the scarf and sunglasses then when she gets to school Jenny is the "new Blair" and they're mean and throw things at her. You're right though, there's nothing to suggest they throw something, I just totally made that up I think lol.