Anticlimax

anticlimax: a sudden drop from the dignified or important in thought or expression to the commonplace or trivial, often for humorous effect

"The child, staring with round eyes at this instance of liberality, wholly unprecedented in his large experience of cent-shops, took the man of gingerbread, and quitted the premises. No sooner had he reached the sidewalk (little cannibal that he was!) than Jim Crow's head was in his mouth."
                                                                     -The House of the Seven Gables
                                                                               by Nathaniel Hawthorne

In the previous passages the narrator recounts Hepzibah's horror, dismay and shame at having to open a cent-shop. This tale of her "second customer" breaks with the distressed groanings of Hepzibah and enlightens the reader as to Hawthorne's views on the matter. The anticlimactic passage implies that Hawthorne does not believe in the old "classes" of society. Hepzibah, perceiving that she must lower herself to an unfamiliar and, at least to her, appalling class, complains and laments. Hawthorne pokes fun at her. He communicates, through this break, that he does not take the problem seriously, and, therefore, the reader should not. Hawthorne uses this device to encourage a major theme, that social classes are unneeded and in actuality harmful.