That would detract from the intention. I don't have it changing often because I'd rather the change happen when nobody is looking. It plays with their memory that way. If they saw it "move" then that would change their entire interpretation of what is going on. They wouldn't be questioning their mind and memory, and instead marveling at a simple technical wonder.

Also, e-paper doesn't change smoothly, so animation is out of the question. It takes some time for images to change, and that would sap it entirely of its magic.

Yep the key here is that it makes you question your memory. "Wait... I could've SWORN that person was looking elsewhere earlier"