Look at the two red marks above the picture. Diverge your eyes as though you are looking through the image into the distance. Diverge your focus into the distance until you see two squares above the image turn into three squares. When you clearly see three squares, at that distance the hidden 3D image will magically appear. Once you perceive the hidden image and depth, you can look around the entire 3D image easily. The longer you look, the clearer the illusion becomes.