[kayge]

And once you have the hang of this technique, congratulations! You can now enjoy those 3D "Magic Eye" images that stumped a significant portion of the population back in the 90s :)

e.g. https://old.reddit.com/r/woahdude/comments/1lxqd0l/the_most_...

[Terretta]

Right, “like a stereogram”!

https://en.wikipedia.org/wiki/Autostereogram