One of the primary characters in The Great Gatsby by F. Scott Fitzgerald is Myrtle Wilson, the woman with whom Tom Buchanan is having an affair. She is the wife of a kind but colorless man named George, and they live above his mechanic shop in what is known as the ash heaps. Wilson's business is not thriving, and he has no clue that his wife is carrying on with anyone else--especially not the rich Tom Buchanan.
Myrtle is not a woman of class, elegance or style when we meet her in her own environment, and that does not change when when we see her in her fancy apartment in New York City.
When Nick sees her for the first time, he describes her this way:
She was in the middle thirties, and faintly stout, but she carried her surplus flesh sensuously as some women can. Her face, above a spotted dress of dark blue crepe-de-chine, contained no facet or gleam of beauty, but there was an immediately perceptible vitality about her as if the nerves of her body were continually smouldering.
She is a sensuous woman, and that is obviously what appeals to Tom. Immediately Myrtle sends her husband away to get some chairs and virtually attacks Tom sexually (which of course Tom does not mind). She demonstrates the complete opposite of class, style, and elegance, which is undoubtedly why Tom picked her to be his mistress.
Once they leave that setting, Myrtle assumes the trappings of class and elegance--things which she thinks money can buy--but ironically displays neither of them. She has a nice apartment, but she filled it with tapestried furniture which is far too big for the room. She has a picture on the wall, but it is a picture of a hen standing on a rock (or at least that's Nick's best guess at what it is). Despite having Tom's money at her disposal, she buys gossip magazines at the drugstore--the same place she buys her perfume. She adores a lavender-colored taxi and buys a dog which she cannot keep because she does not live in the city. More importantly, amid all the trappings which she thinks constitute class and elegance, she and Tom fight loudly and obviously. He punches her in the nose, bloodying it, and yet she stays with him.
Clearly Tom is not having an affair with Myrtle because she is charming and elegant; instead he is with her because she is earthy, sensuous, and classless, like him. In fact, they are a perfect pair, as Tom has all the trappings of elegance and class but possesses neither of those qualities as a person. The irony is that, inside her apartment, Myrtle transforms herself into what she thinks a rich, classy woman must be, but the trappings cannot disguise what she remains: a rather pitiful, unfaithful, woman who lives in the valley of ashes.