the virtual dots are a visual experience which tricks your mind, the dots aren't there and its flashing colors are the extreme experience which leads to thinking the cyan and red dot (up, left) is faster than the dots which are in the middle or bottom. This optical illusion plays games with your mind which can make you feel strange and can lead to confusion. There are hundreds of layers with colored dots and you think its only 6. This experience is harmless, only if you watch it for 4/3 minutes. If you stare at it for too long it will make your eyes tired.