Because details are so important to the characters in the novel, the reader should be prepared to read the novel very closely, keeping in mind that we as readers are meant to think about each detail just as the characters themselves do. This is why Wharton focuses on so many minutiae, most notably things such as Lily's two major facial motions: smiles and blushes. These two motifs come up regularly throughout the novel and take on different meanings, always providing good clues to Lily's feelings.
The first chapter also gives us a sense of the type of language, or diction, that is used throughout the novel. The narrative also uses a number of epigrammatic short, witty sayings that are meant to entertain the reader while providing social satire. For example, Lily jokes that Selden has rescued her from a dull afternoon, and he cleverly replies that it is his mission in life to do so. In Chapter Four, Mrs. Trenor remarks paradoxically that "it's much safer to be fond of dangerous people." (This is the same technique used by Oscar Wilde to convey social commentary in his plays.)
In a larger context, The House of Mirth was written after the publication of Charles Darwin's On the Origin of Species, a book which introduced to the world the concept of survival of the fittest, an idea that works well with The House of Mirth's depictions of social acceptance. Chapter One incorporates the language of Darwin's ideas of natural selection, when Lily begins to think "how highly specialized she was" and that ugly people must, in some mysterious way, have been "sacrificed to produce her."
Chapter Three introduces us to the novel's gambling motif, which will also become very important later in the novel. We are told that Lily has lost almost $300 in that night and is in dire financial straights as a result. Later on, Lily's obsession with gambling will lead her to become involved with the stock market, another form of gambling in which people are ruined financially. It is important to notice that when Lily starts to think of her lack of money, she immediately looks back to her childhood. We begin to see that Lily inherits many of her traits from her mother, who was concerned with keeping up the appearance of wealth even when none existed; when Lily's father announced that he is ruined, the very first words out of Mrs. Bart's mouth were an order for Lily to shut the door so that the servants would not begin to doubt their wealth. Mrs. Bart even tried to cover up their relative indigence to Lily, telling her that her father was merely tired and didn't know what he was saying.
Much like her mother, Lily is obsessed with maintaining the appearance that she is wealthy even when she may not be. Her absolute fears, then, are rejection from the society and "dinginess," which her mother also dreaded. Lily's goal is to end up in a socially prestigious and financially sound marriage. The novel is comprised of a series of circumstances that lead to her rejection from society and eventual death.