A great portrait is always more a portrait of the painter than of the
painted. When we look at a portrait by Holbein or Rembrandt it is of
Holbein or Rembrandt that we think more than of the subject of their
picture. Even a portrait of Shakespeare by Holbein or Rembrandt could
tell us very little about Shakespeare. It would, however, tell us a
great deal about Holbein or Rembrandt.