Wait, that’s different thing. The white wall should should have a black circle, this is commonly referred to as a color afterimage. The same effect can be done with a variety of colored shapes ...

This color illusion is also known as a positive afterimage and is usually at a much briefer timeframe. The same effect doesn't happen with a white sheet of paper because white contains all of the ...

The high-speed rotation of the object, which is synchronized with the scan, produces an afterimage effect on the eye, making the object's shape appear distorted.