Here thereīs another example of this effect: The Technics desk.
It has a four dotted band along the edge of the plate. They all rotate at the same speed (from 33 to 45 rpm) but each band has different number and diameter of dots. 2 of them (I guess the bigger and more spaciated) go clockwise and the other 2 counterclockwise. Itīs a fascinating view.
http://www.netmusic.pl/images/Kopia%20z%20deck.jpg