@Locksmith the illusion is not created by the arrows, but by a little rim outside the circles, if you put your mouse cursor at the very rim you can see that there's not any displacement
@hideki I covered the symbols with my fingers but it still looks like they move?
@5 the illusion is given by a pixel-width rim around the circles. You can use a ruler or something to put besides the circles and check that they don't displace from their place at all.
@hideki thats a lie. cover the arrows and you can see the movement