How can I compare and contrast the images, tone, and themes of the poems "My Last Duchess" by Robert Browning and "Richard Cory" by Edwin Arlington Robinson?

"My Last Duchess" is a dramatic monologue spoken in first person by the Duke; "Richard Cory" is a ballad narrated in first person by a citizen who knew Cory from a distance. The poems have much in common but have many differences as well.
The images in "My Last Duchess" center around artwork, specifically the painting of the Duke's former duchess and a sculpture of Neptune. The woman is objectified by these images, as well as the association with other objects such as her "white mule" and a "bough of cherries." Similarly, Richard Cory is objectified by the townspeople by his clothing and his glittering appearance. Both the Duchess and Cory spoke with kindness to others; the Duke reacted negatively, but the townspeople responded positively. "Richard Cory" contains images of poverty and hardship among the lower class citizens; "My Last Duchess" has only images consistent with upper-class life.
The tone of each piece is quite distinct from the other. The tone of "Richard Cory" is measured, calm, and somewhat detached. The tone of "My Last Duchess" is somewhat manic and unpredictable as the Duke vacillates among the emotions of pride, irritation, rage, and desire to please. However, there is some similarity in tone in that the narrator of each poem is primarily focused selfishly on himself rather than being overly saddened by the passing of the person being discussed. A feeling of jealousy also pervades each poem.
The themes of the poems are similar in that both contemplate the effects of jealousy. In "Richard Cory," the jealousy of the townspeople may have resulted in Cory feeling increasingly alienated, which may have furthered the depression that perhaps led to his suicide. In "My Last Duchess," the Duke's jealousy leads him, presumably, to having his wife killed. Thus both poems show the destructive power of jealousy. Another strong theme in both poems is that money can't buy happiness. Cory was so unhappy that he ended his life, despite being "richer than a king." The Duke has immense wealth from being at the highest level of aristocracy, yet he allows himself to be made miserable by perceived slights from his wife. Each of the poems has a unique theme it does not share with the other. "Richard Cory" has a strong theme of depression, alienation, and suicide, while "My Last Duchess" has a theme of the corrupting nature of power.
Although "My Last Duchess" and "Richard Cory" are different types of poems, they share similarities of tone, images, and theme while remaining distinct in many ways.