That’s one of those images that you can mentally reverse, like this one:

The technical term for the illusion is “The Twirling Little Naked Vixen Effect.”
Here’s another:

If you reverse it quickly several times it gets kinda Freudian and you’ll have to go to confession for having those impure thoughts. Speaking of impure thoughts (now that you’re already guilty as hell for having them) you might as well have some more on this edition of The Overnight Open Thread.