Staging is the presentation of an idea so that it is clear. This idea can be an action, a personality, an expression, or a mood. The key idea is that the idea is made clear to the viewer.
An important objective of staging is to lead the viewers eye to where the action will occur so that they do not miss anything. This means that only one idea at a time occur, or else the viewers may be looking at the wrong thing. So, the main object should be contrasted in some way with the rest of the scene. A good example is motion, since the eye is drawn to motion in an otherwise still scene. In a scene with everything moving, the eye is drawn to a still object.
The animator must use different techniques to ensure that the viewer is looking at the correct object at the correct time. For example, in Luxo, jr. The Father appears first, and so is the center of attention. Then the son bounds in, moving rapidly, so the center of attention shifts to him. At a certain point the son stops and looks up at the father, refocusing the attention on the father.
In the early days at Disney all characters were black and white, with no gray. All action was shown in silhouette (to the side), because if a character moved its black arm in front of its black body it would disappear, so the action had to be against the white background. The Disney animators realized that even without this technological limitation action was more clearly visible in silhouette.
Even with modern color 3D graphics, silhouette actions are more clearly delineated and thus to be preferred. over frontal action. An example would be a character waking up and scratching its side, it is easier to understand what it is doing than if it scratched its stomach.