Some of you will already be acquainted with the art of 3-dimensionally looking at a picture. Some of you will not. So here's a brief explanation. Although there isn't really anything to explain. I don't know how and why it works, I only know THAT IT WORKS. Here's what you should do to reveal the subject of the picture:
Take the picture straight in front of you and keep your head upright. You need to focus on any point behind your computer screen. Now keep your eyes the way they are (so don't stop squinting, it's actually not really squinting, I like to call it reversed squinting :)), and watch the picture. An image should appear. If not, keep practising! It's not all that hard :D

Here's a nice and easy one to start with.

Awww... doesn't this soften your heart? :)

Cool huh?

Grrrowl, watch out!

This one's kind of tough to see. You might be seeing it the other way around first: what's supposed to stick out of the screen towards you, can appear as a hole in the screen, and reversed.