O. Henry describes the couple's prized possessions early in the story.
Now, there were two possessions of the James Dillingham Youngs in which they both took a mighty pride. One was Jim's gold watch that had been his father's and his grandfather's. The other was Della's hair. Had the Queen of Sheba lived in the flat across the airshaft, Della would have let her hair hang out the window some day to dry just to depreciate Her Majesty's jewels and gifts. Had King Solomon been the janitor, with all his treasures piled up in the basement, Jim would have pulled out his watch every time he passed, just to see him pluck at his beard from envy.
Women in O. Henry's time customarily let their hair grow exceptionally long. According to O. Henry, Delia's hair "reached below her knee and made itself almost a garment for her." Few women would want the trouble of having such long hair today, but women in the early 1900s were usually confined to their homes, like Delia, and had the time to wash, brush, and arrange their long hair in bouffant styles which can be seen in the drawings of the so-called Gibson Girls by the popular artist Charles Dana Gibson. It was only because of the abundance of her fine hair that Delia was able to get so much money for it. When F. Scott Fitzgerald published his story "Bernice Bobs Her Hair" in the 1920s, it recognized the revolutionary changes taking place among young American women.
Jim's gold watch was distinctive because good watches were not common possessions in O. Henry's day. A dependable watch had to be big and heavy. Jim's watch must have been exceptionally well made if it passed from his grandfather to his father and to him and still kept good time. Wristwatches were unknown because watch makers were unable to make time pieces with such small inner mechanisms. Women did not usually own watches. There were many more clocks on office buildings and churches, and big free-standing clocks are still to be seen on some downtown sidewalks in cities (although not many of them show the right time). Big Ben in London is the world's most famous clock. Most people had to rely on these public clocks to tell the time.
O. Henry focuses on Delia's hair and the torment she went through before and after selling it. The irony in the story mainly has to do with the fact that she sacrificed her beautiful hair in order to buy a watch fob for Jim's watch, only to find that he had sold it to buy combs for her long hair. But the emphasis throughout the story is on Delia's love and Delia's sacrifice.