Train Trouble

So many questions about this next story. Why was this girl just laughing at this random couple? Had they done something to prompt it? Because right now, I have this image in my head of the couple looking over and seeing a girl on the next seat, just pointing and laughing at them for no good reason.

And on a crowded train, where there’s not that much room to get moving, how did this girl trip so hard that she got a nosebleed? Did she just bang her face into the back of the guy’s head? I guess karmic retribution doesn’t have to follow the laws of physics.