1. The chicken because without one there would never be an egg. The egg can create a chicken however you have to think about how that egg got there.
2. Dust and particles in the air can collect on your towel like what happens to fans they can collect dust.
3. Square boxes are a lot cheaper and common than circular boxes. It would also mean that the pizza would have to be the exact size to fit and that can be difficult when pizza men are in a rush to make a bunch of orders at once.