In "Arrangement in Black and White," by Dorothy Parker, the irony is conveyed through the host's responses to the woman.
<em>"He's over there by the bookcase," she said. "Let's wait till those people get through talking to him. Well, I think you're simply marvelous, giving this perfectly marvelous party for him, and having him meet all these white people, and all. Isn't he terribly grateful?"</em>
In the above statement, the host's contradictory statement and the use of the word <em>"grateful"</em> convey irony. In the setting, the guests remain the innocent parody of the society's prejudice whereas, the audience recognizes the racism.