Spinning Dancer Optical Illusion: Clockwise or Anti Clockwise?

Look at the picture below and guess which direction is the dancer spinning? Is she spinning is the clockwise direction or is it the anti-clockwise? The Spinning Dancer, also known as the silhouette illusion, is a kinetic, bistable optical illusion resembling a pirouetting female dancer. The illusion, created in 2003 by web designer Nobuyuki Kayahara,