This curtain is the first reference to the Duke's selfish personality. The Duke uses the curtain as a method of controlling his wife, even after her death. "The Duke can finally keep all her smiles to himself" (Beckham). In line two, the Duke talking about the painting says, "looking as she were alive", letting us know that the Duchess is dead. He mentions this again in line 47. The whole poem starts developing around the fact that the Duchess is not longer alive. The Duke's possessive personality starts showing. .
The Duke's desire of control appears more and more evident with every word and every sentence he says. An essay about "My Last Duchess" published Planet Papers points out that "the speaker tries to convey to the people that he shows the portrait to (show) that he is in control". When the Duchess was alive he wanted to control all her smiles. The Duke considered that "his wife should be for him and his pleasure only"(Planet Papers). She should not be flirting with other men. Nevertheless she was not trying to flirt with other men; she was only trying to be nice and polite to them. The Duke even tries to control his wife after she is dead, by covering her portrait with a curtain.
The Duke also shows being a very controlling personality because he is monopolizing the whole conversation between him and the envoy. The Duke talks without stopping and without letting the envoy say one word. According to Abeid at al "he also seems to direct the actions of the person he is addressing with comments such as "Will't please you rise?" (line 47) and "Nay, we'll go / Together down, sir" (line 53 and 54).
Also, ""My Last Duchess" illustrates the irony of control"(Beckham). Even though the Duke feels controlling of everything, he really has much control as he believes. He could not control his wife's blushing and smiles. The only solution he found to stop the situation was to have her killed.