Ehh. They way you initially cut the paper constraints how you later can fold it. If the square was cut any smaller you wouldn't be able to fit the coaster throu

Ehh. They way you initially cut the paper constraints how you later can fold it. If the square was cut any smaller you wouldn't be able to fit the coaster through no matter how you try to fold the paper. The square and its size is a constant in this problem, using a scissor to make the square bigger after its given to you would be considered destructive. In the postcard problem there is no such constraint as you are allowed to cut in whichever form/size you want.