Caricature
What is a caricature? The key difference between caricature and drawing a portrait of someone is the intentional distortion of the subject in caricature. This distortion is difficult because the features of the subject are what makes the subject recognizable, when you start fooling around with these features, then you run the risk of losing the likeness of the subject. So in order to keep the likeness you should understate features that are minimized on the subject and over-maximize the features that are maximized on the subject. If you go against the grain and minimize a person's large mouth you will loose the likeness. Who ever heard of a drawing of .... with small lips and mouth? Or ... with a small, little baby chin? It just wouldn't look like Jay or Mick.