I understand that but either way when you look at the folder properties surely it wouldn't just show up as using 0Kb (or something small). Wouldn't it still show you the size of the folder? It just doesn't make sense that it would also hide the amount of memory a folder is using.
Not true - if the file manager doesn't have permission to view particular folders, it can only display existence of such folders based on the parent folder/directory header, but no other details. It will therefore default to display such folders with 0 byte size!