I don't think they are *required* to lay down, but if they don't, then the other kids behind them can't see. If your child didn't want to lay down, I would think they should get out of the other kids' way, and sit, stand, or whatever in the back or off to the side. If they want a good seat for the movie, they should be lying down so as not to disturb the other kids trying to watch. Our DS(3 yrs.) was not a big one for lying down either, but he did like to hang out on the side near some sort of foam thing (don't ask me what it was!), and there was no problem with that.