Visual medium I think is the most potent medium. Our ability to catch minute details in visual form is a lot stronger than our other senses. This picture shows two pictures of Mickey Mouse done quite differently but at one glance we can tell it is a Mickey Mouse. Even if it is not a complete picture but just the silhouette of a small part of the head, we can still recall it as Mickey Mouse. Inspite of this when we try to communicate anything visually we are somehow compelled to provide as many cues, not trusting the ability of the other person to understand it.