Usually, I like to share illusions you might not have seen before. And, with 73 million views and counting, Zach King does not need my help.
Even so, these optical illusions using peculiar pieces of furniture and the human brain are simply too stunning not to share.
Most take advantage of the fact that the human brain uses context clues to estimate how far away objects are.
We can usually judge an object's distance because each eye is provides a slightly different point of view. Our brain combines those two images to place the object in space.
When the illusion is on a screen it becomes a 2D representation of a 3D object and our brain can only place the object in space based on the size they should be.
For example, in this shot from elf, our brain knows where in space the elf in blue is based on the fact that her desk appears larger than the elves behind her.
However, because her desk appears to be the same size as Buddy's desk, our brains assume that they must be side by side and Buddy must be much larger than her. In reality, Buddy is at a much smaller desk sitting much closer than he appears.
The illusion would not be ask strong in real life because our eyes would be able to view the set from multiple angles.
The same psychology explains how my mate, Melbourne magician Dom Chambers can chug four beers in ten seconds.