Quick! Draw a coffee cup. Or sketch a dog. Or a car. Chances are, if you ask someone else to draw the same object, they'll sketch it from the same angle you do. This is called canonical perspective, and it has an effect on everything from your mental image catalog to the icons on your computer right now.
I have a set rule to never do anything a psychologist asked me to do. You never know when they're going to make you think that you committed murder. So if I had been approached by three of them and asked to draw a coffee cup, I probably would have made a wild stab at them with my pen and run. If I had participated - like one of the many people from all around the world who were asked to draw a coffee cup by Stephen Palmer, Eleanor Rosch, and Paul Chase - I would probably have drawn something like the image of the coffee cups below. Granted, there are only so many ways you can draw a coffee cup, and some people interpret the cup as more bowl-like or more narrow and upstanding. But there are numerous angles from which to depict a cup, and every drawing uses the exact same one. Almost all the cups are seen, by the viewer, from above and slightly angled so the nearest edge is lowered. Even the one large drawing at the top right, which seems entirely in profile, gives itself away by making the rim of the cup an oval instead of a line. We're seeing the cup from above, and, for the most part, from the side.