Well, take a look at these pictures of elephants drawn 500 years ago based on descriptions by early explorers. Our children learn to read by putting words and letters together with pictures.
Pictures are concrete representations of reality.
Words are abstractions. Because every reader builds a different picture, it's just impossible for a movie to live up to every reader's imagination. Then when you read the book, you envision the film's actors as the main characters. A verbal or written message is subject to interpretation. A message contained in a picture is concrete.