[0] https://en.wikipedia.org/wiki/Print_Gallery_(M._C._Escher)
[0] https://pub.math.leidenuniv.nl/~smitbde/papers/2003-de_smit-...
But, as with all jokes, the punchline isn't funny at all without the setup.
Even in those terms the answer given isn't really an answer because it just gives an expression with undefined variables.
This kind of risks obscuring what's actually going on.