Spinning Silhouette Illusion

Cool illusion. At the first glance, she is spinning clockwise (or otherwise), but then, you can change her direction. Here are some tips on how to do it:

• You have to look down at the shadow, keep your eyes there for some seconds and then slowly move your eyes upward.
• Sometimes my brain even changes the direction when I look at different parts of the figure. Dont stare at her, keep your eyes moving up and down.
• when she turns clockwise she has the right foot up.. when counter-clockwise its the left foot.. just tell yourself which foot is up and she will turn in that direction.

Any explanations?

via. @ funlimited.co.uk.