What recursion is

A recursive function is one that calls itself.

It doesn't try to answer the whole question. It shaves the question down by one step, hands the smaller version to a fresh copy of itself, and waits. That copy does the same thing. So does the next one.

Eventually a copy gets a version small enough to answer without asking anyone. That's the base case. It returns a value, the copy below it returns, and the answers unwind all the way back up.

meow(4) waits on
meow(3) waits on
meow(2) waits on
meow(1) waits on
meow(0) returns "meow"
and every layer above returns in turn

Take away the base case and nothing ever returns. The calls keep stacking until the machine runs out of room to hold them. That failure has a name, and it is the most famous website in software.

Where the look came from

The art direction on this site is lifted from a profile picture: a face in hard side profile, lit from one edge, with smaller copies of the same face nested inward until they vanish into black. It belongs to Vlad Tenev, and it has been sitting on a very visible timeline for a while.

It reads as recursion rather than motion. A trail of motion keeps every copy the same size and strings them out behind the subject. This does the opposite: each copy is smaller than the one before it and sits inside the outline of the original. A face containing a face containing a face.

That structure has a name in art, mise en abyme, and a name in design, the Droste effect: an image that contains a smaller copy of itself, which contains a smaller copy of itself.

To be clear about it: this is our reading of a public profile picture, not his. He has nothing to do with this coin and has never said a word about it.

Recursion in the wild

Once you have the shape in your head you start seeing it everywhere.

No base case

Most of those examples terminate. The doll stops opening, the algorithm returns, the chain hits genesis.

This one doesn't. That's the whole joke, and it's the only thing $MEOWEOW promises.