What do we call this?
Hand signs on the wall? Hand gestures?
Shadow play, hand shadows, or shadow puppets will all probably be understood, although when I hear "shadow puppets" I usually think of things like this:
An older name for shadows thrown by hand is simply hand shadows. I've got this book, originally published in 1859, facing me on my bookshelf right now:
You can see how the popularity of the terms has changed over time.
- A play presented by casting shadows of puppets or actors on a screen. Also called shadowgraph, shadow show.
(AHD)
Its just called hand shadows
. If a story is told using that then its called shadow play with hands
. A shadow play may consist of hand shadows
and shadow puppets
(shadow puppets are usually cut-out shapes of puppets).