One device that develops the central idea is irony. In this case, the irony works in a couple of ways. First, the reader watches a woman receive devastating news about the death of her husband, but instead of grieving, this woman begins to laugh and celebrate being rid of his overbearing presence. Later, the woman and the reader learn that the husband is actually alive. Instead of being overjoyed, the woman drops dead.
None of the woman's family is the wiser, but the reader knows that the woman was excited about being single, independent and free. The limited point of view allows the reader entry into the woman's mind, but not the minds of her family and friends gathered to help her through her ordeal. This insider information allows the reader to understand her true feelings and thus understand the theme of the story.
Women in marriage during Chopin's time were often dependent upon and a bit subservient to men, but the desire to be rid of this oppression dwelt in many, if not most women. In fact this timeless theme of women and identity rings true with women of all times.