I got this on the Badulla bus, I think it was about 50 Rupees. It’s pretty awesome. A Chinese knock-off of, I think, this product, this static book creates what looks like a movie image when you drag the attached film across the page. It’s pretty cool.
I’m not sure how the illusion actually works. I guess there are actually two plus states in the disjointed printed image. When you move the film one is obscured at a time, making the image appear to movie. They call it ‘magic’. I’d settle for cool.
I think it works because the lines in the picture give the impression of movement when you draw the frame on top across.