Bertolt Brecht at nonsite:
Truth in Art. Artists have almost always discouraged those who wanted to see a criterion in the degree of similarity of their images of reality with reality itself. At least in our time, painting considered as the capacity to paint similarly was seen as mere craftsmanship; it had nothing to do with art. Even with jobs where it concerned copying—be it a garden, a pet or a family member—value was placed on perceptibility, one must be able to have the illusion that it was the beloved object. (Here the buyer was somewhat sensitive when artists were only delivering him their associations on the occasion of the object.) In general, artists probably arrived at the fact that the optical use that one could make of an object was as pleasurable as any clever use which one could make of an object that has been manipulated. (One can also discover the pleasure in the body part that lines up cleverly.) The enjoyment of the cherries of Cézanne is thoroughly understandable, though perhaps not those of Apollonius, which birds pecked at.
more here.