Consider this painting:

It is by Magritte. It is entitled, 'This is not a pipe.' It is not. It is a painting of a pipe.
The implication?
Art is not a mirror of the world. You can see this with this piece by Duchamp:

An ordinary urinal is placed inside the art institution. It becomes art.
Duchamp did the same with this bicycle.

Such is the power of the art institution.