He doesn't have to scoot over, the seats are too narrow to do much scooting. You honestly believe that a full size man and a life size manikin were sitting in that seat?
We can't see him move because the top of the seat is outside the frame for too long. Maybe he leaned over to look out the window.
"What say you to the image that rx posted which claims to do just that?"
Where is it posted?
He’d have to scoot over to be seated straight up with his head on the window side of the neckrest. If he simply leaned over, as you suggested, his head would have been at an angle, not sitting straight up.
You ever hold a kid in your lap?