This channel is dedicated to stereograms, also called autostereograms.
A stereogram is an optical illusion of stereoscopic depth created from a flat, two-dimensional image or images. At first sight a stereogram looks like an abstract image made of repeatable patterns. But if you look at it in a special way, the hidden 3D picture will magically appear. What you will see is a relief object or objects wrapped with the pattern you can see in the 2D picture.
In order to see the hidden 3D shapes in these images, a special viewing technique is required.
Learn here:
hide3d.com/how