Petra had come to the common room to watch TV while she did her nails, but she hadn't gotten quite as far as the 'doing her nails' part yet. This was because, while channel surfing for something to watch while doing her nails, she'd encountered
a flashback. At first she just sort of stared at the TV screen, stunned to realize they still had boy bands in this dimension--she'd kind of thought they'd worn out their welcome years ago, and had frankly found that a relief--and momentarily insulted that the song implied that the only reason someone would wear makeup was "to cover up." Hello, maybe the fictional girl in the song just liked makeup. But then one of these babyfaced teenagers with hair that looked like a bunch of seagulls had attacked it earnestly sang that to prove he was right, he put it in a song, and the idea that being in a song made something right struck her as so funny the whole thing hit her at once, and she wound up laughing so hard tears ran down her face and she fell off the couch.
Okay. This wasn't exactly a flashback, although the terribleness of that hair was pretty familiar. There was the fact that, "You don't even dance!" as Petra hauled herself up via the coffee table to shout at the screen before collapsing with the giggles once again.
So, yes. Anyone entering the fifth floor common room, or simply passing by, would find a British boy band singing on the TV and Petra West laughing herself sick. Business as usual?
((I had to. Open common room is open. Come mock One Direction with Petra! Or defend them. Whatever floats your character's boat.))