"e", or Euler's number, is a constant used in maths because it has useful properties in logarithms and some other things. Basically just like pi except for logarithms instead of circles. Like pi, it's an infinitely long series of non-repeating digits. The crime you have witnessed in the post is a shitload of mathematical operations applying e to e in various ways in order to get (very close to) pi. Like saying "I'm going to make 14 using only 2" and then saying (2^2^2)-2, except instead of 2 and 14 you've got e and pi

Donno if it's part of the joke but there is a beautiful equation:

e^iπ^+1=0

So once you allow yourself to use i and log and stuff, you get a nice and simple equation

They're also doing some shenanigans with the variable of integration. I bet it would look a lot more palatable if they were changed