What is the effect of starting My Last Duchess by Robert Browning with a piece of art, and ending the poem with another piece of art?
If possible I would also very much appreciate any analysis points on this particular poem.
This is an interesting question because it goes to the heart of an important theme of the poem--that is, the self-absorbed personality of the Duke.
The Duke begins the monologue by pointing out that the portrait is of "my last duchess," the emphasis being on my, and ends his monologue by referring to another work of art that was "cast in bronze for me!" In the intervening lines, although we learn something about the Duchess's personality--that she's easily pleased, polite, and democratic--much of what we learn is about the Duke's autocratic, self-centered, prideful, and, quite possibly, murderous personality.
Throughout the poem, in almost every observation that the Duke makes about the Duchess, there is either an implicit or explicit absolute disapproval of her behavior, particularly her willingness to show gratitude for even the smallest of things. The Duke's reaction to this behavior says as much about his true nature as it does about the Duchess's, and the picture we get from the Duke's own mouth is one of barely-concealed rage at his wife. The fact that he never bothers to tell his listener what happened to the Duchess is, at the least, unusual. More important, his lack of feelings for the Duchess is ominous.
Browning's balanced beginning and end, I think, are meant to drive this point home: we are looking at a jealous, vengeful man who is so wrapped up in himself that he cannot even see (and he may not even care) how others perceive him.