Images pretend to reveal the heart

Wherever you find a Raphael, a Rubens, a Michelangelo, a Carracci, or a da Vinci (and we see them every day,) you find artists copying them, and the copies are always the handsomest. Maybe the originals were handsome when they were new, but they are not now.

The colors are dimmed with age; the countenances are scaled and marred, and nearly all expression is gone from them; the hair is a dead blur upon the wall, and there is no life in the eyes. Only the attitudes are certain. …

There is not one man in seventy-five hundred that can tell what a pictured face is intended to express. There is not one man in five hundred that can go into a court-room and be sure that he will not mistake some harmless innocent of a juryman for the black-hearted assassin on trial.

Yet such people talk of "character" and presume to interpret "expression" in pictures.

Source: The Innocents Abroad by Mark Twain