Satou-san looks like he wants to go collapse somewhere. Konno-san looks like he's completely resigned. Koichi-san seems to be saying "Oh, don't mind me, I don't even belong here, now I'm just going walk away so please forget I was ever here..." And my friend got it perfectly when she said that it looks like Ohira-san was about to pick someone's pockets.
Didn't Hikaru mention in a recent interview that she struggles with sleeping when they have something to do the next day because she gets so nervous? That's probably why she looks like she needs a nap.
It must be hard on someone who loves sleeping to get little of it, oho.