Proper timing is critical to making ideas readable. It is important to spend enough time (but no more) preparing the audience for: the anticipation of an action; the action itself; and the reaction to the action (the follow through). If too much time is spent on any of these, the audience’s attention will wander. If too little time is spent, the movement may be finished before the audience notices it, thus wasting the idea.
The faster the movement, the more critical it is to make sure the audience can follow what is happening. The action must not be so fast that the audience cannot read it and understand the meaning of it. 4
To make sure an idea or action is unmistakably clear, the audience’s eye must be led to exactly where it needs to be at the right moment, they must not miss the idea or action. Timing, as well as staging and anticipation are all integral to directing the audience’s eye. A well-staged anticipation will be wasted if it is not timed properly. 1
It is important that only one idea is seen by the audience at a time. If a lot of action is happening at once, the eye does not know where to look and the main idea will be overlooked. The object of interest should be significantly contrasted against the rest of the scene. In a still scene, the eye will be attracted to movement. In a very busy scene, the eye will be attracted to something that is still. Each idea or action must be timed and staged in the strongest and simplest way before going on to the next idea or action. The animator is saying, in effect, "Look at this, now look at this, and now look at this." 3
In most cases, an action should not be brought to a complete stop before starting another action; the second action should overlap the first. This slight overlapping maintains a flow and continuity between whole phrases of actions.
In Luxo Jr., it was very important that the audience was looking in the right place at the right time, because the story, acting and emotion was being put across with movement alone, in pantomime, and sometimes the movement was very subtle. If the audience missed an action, an emotion would be missed, and the story would suffer. So the action had to be timed and paced so that only Dad or Jr. was doing an important action at any one time, never both. In the beginning of the film, Dad is on-screen alone and your eye is on him. But as soon as Jr. hops on-screen, he is moving faster than Dad; therefore the audience’s eye immediately goes to him and stays there.
Most of the time Jr. is on-screen, Dad’s actions are timed to be very subtle, so the attention of the audience is always on Jr. where most of the story was being told. If Dad’s actions were important, Jr.’s actions were toned down and Dad’s movements were emphasized then the attention of the audience would transfer to Dad. For example, when Jr. looks up to Dad after he’s popped the ball and Dad shakes his head, all eyes are on Jr.