Touching and drawing are both gestures of confirmation. You do either to acknowledge the presence of an other—or of yourself, which has been changed into an “other” by a reflective surface like a mirror.
The desert rat above is just an outline. Only enough information is given to identify the rat, and no more.
It is less a drawing of a rat than a drawing of the boundary between the rat and the rest of the world.
It is a map of where the world ends and the rat begins.