How was understatement used in The Great Gatsby?Understatement; a statement that is restrained in ironic contrast to what might have been said

In the opening chapter of the book, Nick, the narrator, describes where he lives on Long Island, and specifically, West Egg.  He calls it "less fashionable" than East Egg and in doing so is using understatement since East Egg is very glamorous and populated by some very rich people.  West Egg, too, has its very rich people (Gatsby, for example).  Then when Nick gets to the Buchanan's house, Tom comments that he has "...a nice place here" when he lives in an extravagant mansion.  Most of the descriptions that Nick gives us are detailed and accurate, and he uses more irony than he does understatement, but in describing the wealth and extravagance of both the Buchanans and Gatsby, there is some understatement.  Both the Buchanans and Gatsby spend great amounts of money - the Buchanans because they are used to it and Gatsby because he wants to impress people, especially Daisy. Nick gives Gatsby's parties a vivid accounting of the elaborateness, but he holds back a little on other aspects of Gatsby's surroundings.  In chapter 2, when Nick is describing Myrtle, he uses some understatement when he tells about how she changes (both literally in changing her clothes and figuratively in changing her persona) once she gets in the car with Tom and they go to the apartment in the city.  Myrtle puts on airs as easily as she puts on new clothes. Nick is subtle in this description using understatement.