This is the type of illusion that would get people marked as witches back in the old days. There was probably some clever genius woodworker who got the idea to make this (let me clarify that I have no idea how this is made or what it is), so he made it and showed everyone. Their feeble brains couldn't process it so he was immediately labeled a warlock. That's what people do. They don't understand something you're saying and you're immediately labeled a witch or a warlock. People, am I right?
I really need to hold this in my hand to fully understand what's going on. It's not a good use of my mental energy to spend another day looking at this picture. Even my friends and my family are starting to worry about how much I'm looking at these photos, and the obvious damage looking at them is doing to my brain.