True sadness is generally expressed by lying face down on the floor.
If he is truly, truly angry this is accompanied by head banging. If Me Too feels you are not understanding the true depths of his anger he will follow you from room to room and bang his head against the wall once he is sure you are watching. (He gets this from his Uncle by the way.)
I was horrified to get a glimpse of his forehead around lunch time today. It seems that he did some damage in the last 24 hours. It looks worse in person than it does in the photo.
I guess it is time to do what my Mom used to do with my brother...pick him up and put him on a soft surface.