Composition refers to the organization, arrangement, and combination of objects within the borders of a drawing space. For a great drawing, you want to bring the eyes of the viewer toward your center of interest within an aesthetically pleasing composition.
The idea that clockwise motion represents the forward motion of time so powerful that it's hard to look at such a watch or clock without having the slightly unsettling feeling that time is running backwards.
Since this gyro is rotating in a clockwise direction, point A will be where point B was when the gyro has rotated 90 degrees. The same goes for point C and D. Point A is still traveling in the upward direction when it is at the 90 degrees position in FIG 2, and point C will be traveling in the downward direction.