That’s my last Duchess painted on the wall, Looking as if she were alive.

The image is a painting of Lucrezia de' Medici, and though this was painted for her brother one year after her passing, this painting could be used as the stand-in for the image the Duke is describing. The Duchess' somber gaze is antithetical to how the Duke describes the Duchess as a person, which makes the reader question how much truth could the Duke be speaking. Is it possible that the Duke is imagining a smile on her face because he feels guilty? Is the Duchess' stoic look a reflection of her feelings, or was it "by design" as the Duke later states?