How does the author use irony in the novel, The Age of Innocence?

Wharton uses irony in The Age of Innocence to reveal the hypocrisies she sees in New York society. When May and her parents go to St. Augustine for the winter, Mrs. Welland arranges for a group of servants to help them make the best of it. As they all sit down to a sumptuous breakfast, Mr. Welland tells Newland, "You see, my dear fellow, we camp - we literally camp. I tell my wife and May that I want to teach them how to rough it." Later, in chapter 26, Mrs. Jackson condemns the vanity of wearing extravagant new dresses, when the proper thing is to buy dresses and wait a few years to wear them. She then describes another woman's dress that she remembers from the previous year, and how a panel has been changed to make it look new. She apparently cannot see that such minute attention to and memory of what ladies wear is exactly what feeds the vanity she berates.