I used to think look past just means ignore until I heard this sentence used by an American talking about a picture saying,
"If you look past the picture, you can see a horse."
I gave it an online search and the related pages show hidden 3D pictures. I can tell then the picture he was talking about was one of these. The thing I'm not clear about is how you do it. How do you look past a picture exactly? Is it making the picture closer to your eyes or vice versa? Is it looking at the picture from sides? or something else?!
Best Answer
When you look at an object normally, you look at it with both eyes. Each eye has a line of sight, and those lines of sight cross at the object's surface. Looking at the picture means that the crossing point is on the picture's surface.
[Source]
Eyes converge on the surface of the image
Looking past an object means that the lines of sight cross behind the object. If you can get your lines of sight to cross at the right distance past the surface of one of these special pictures, there is an illusion of a 3-D image. This happens because these special pictures are repetitive, and focusing on the right distance past the picture's surface makes the repetitions line up. Small differences in the repetitions create the 3-D illusion.
[Source]
Eyes converge past the surface of the image