How does Eugene O'Neill use imagery in The Emperor Jones?

O'Neill says of Jones in his stage directions that "his eyes pop out," relying on a stereotypical image of fear that is seldom applied to white characters. O'Neill's characterization of Lem in the final scene is especially insensitive. He describes Lem as "a heavy-set, ape-faced old savage of the extreme African type, dressed only in a loin cloth." And Lem's naive belief in the magic of the silver bullet is expressed in words that make him sound like a caricatured Native American Indian: "lead bullet no kill him. He got um strong charm. I took um money, make um silver bullet, make um strong charm, too. . . . Yes. Him got strong charm. Lead no good."