How does the author use symmetry in the story, The Wives of the Dead?

The story is organized symmetrically around pairs. Two sisters-in-law of two brothers learn in two successive days about the deaths of their husbands. They then have almost identical experiences during the night, each awakened by a messenger bearing good news about her (supposedly dead) husband. Each takes a lamp from the hearth to address her visitor at the window while the other is asleep, and each declines to wake the other, though for different reasons. This symmetrical structure allows Hawthorne to contrast the women's characters, showing how each responds differently to a similar experience.