Crayon in Stereo
It can be difficult to see stereograms on large screens, so I recommend viewing this page on your phone. You also won't be able to see the stereographic effect if you don't have good vision in both eyes. If you bring the image close to your face and unfocus, and then slowly draw the screen back from your eyes, trying to see 3 images instead of two, the third image should eventually come into focus in 3D.