Have you ever seen any confusing photographs? If no, they are normal non-photoshopped photographs which are taken at right time in a different perspective. Only thing is that, these confusing photographs will give you shock at first glace, but when you spend little time to understand the image, you will break the ice.
The effort you take to break this ice will give you slight pain in your head, its because your mind is trying to focus these photographs in a different perspective. When you find the right perspective to look at these images, then you get to see the original photograph.