We are the Western World. We read, see, think. Left. To. Right. We can't help it.
..The problem with Top to Bottom is that it's unAmerican. We want to begin in the depths and climb our way upward. But our typographic system argues against this and wins, and images follow suit.
..What you have to be careful to remember about Big and Small, is that they can extend to infinity in either direction. Consider: Big can always be bigger and Small smaller. The atom is the Universe and vice versa. And they're both identical.
..Left to Right, Top to Bottom, Big and Small; on a two-dimensional plane, all of these tools rely on a relative truth. Now we come to In Front Of and In Back of, which for us are big, fat lies. Very useful though, and the first of many at your disposal.