Robert Browning’s main point in “My Last Duchess” is that the Duke values art but cannot appreciate beauty in reality. The truth is that reality contains infinitely more beauty than art, and no artist can hope to produce anything more than a crude copy. The Duke is incapable of expressing what it was about his late wife that displeased him, but it was the fact that, being real and being human, she lacked the professional polish and perfection that an expert artist can give to his copy.
Obviously, a beautiful young woman is far more of a “wonder,” more of a masterpiece of divine creation, than a two-dimensional copy of that same young woman in oil paints. But the Duke appreciates his copy more than he could ever appreciate the subject in real life. He sits there coveting and admiring his painting of his deceased wife, but he could only find fault with her when she was alive.
Fra Pandolf was well aware that his work at best was only a crude representation of reality. The Duke quotes him as saying, “Paint / Must never hope to reproduce the faint / Half-flush that dies along her throat.” The insensitive Duke thinks “Such stuff / was courtesy”—but the artist is telling the simple truth. Even the greatest artist must never hope to capture the subtle beauties of nature. Art is nothing but imitation. The artist can only remind us, or teach us, to appreciate the beauty that exists naturally all around us.
The Duke also prizes his sculpture of Neptune taming a sea-horse, but he would probably be blind to the ever-changing spectacle of the turbulent ocean which inspired the conception of the god Neptune and, many centuries later, Claus of Innsbruck’s cold, immobile bronze statue.