I would not claim it's more obvious, but this is an illustration on the cover of a mathematics journal. It should show mathematics, not an artistic misunderstanding. If people have to stop and think through the math to understand it, then it is doing its job properly. As it is, it just gives a bad name to the artistically minded.
You can think through the maths but you don't have to. This is one of those cases were pattern recognition is enough and no more thought is needed. That is to say, a mathematician should (and has no excuse not to) have seen Euclid's illustration of Pythagora's theorem which the journal cover is a very obvious representation of, so there should be no confusion.
