I agree the guys head is a little strange. The way it fits into the scheme of things doesn't quite work. If you are hellbent on keeping him in there then you might want to move his head down and put more thought bubbles leading to the big idea. But I recommend that you ditch the head all together...
I like the idea of the head, but not the way it appears here. I'd make the head huge and subtle and move the action to the head's interior, but that's just me.