Steady on now: there's an interesting psychological effect going on. A well known art exercise is to draw a subject upside down, particularly a person or a scene with a clear usual orientation.
When you take something you're very familiar with and turn it upside down, you see all the details - volume, shape, distance between points, geometric similarity, colour - with fresh eyes. With art, it becomes easier to draw a human figure because it discourages symbol drawing. With a map, I find it helps me realise how close certain points are to each other, how small politically significant regions are, which lattitude different climate bands sit at, and so on.
A mug is a pretty boring object which we're all used to seeing upside down and which doesn't have many interesting features, so of course turning it upside down will not reveal anything interesting.