O. Henry carefully portrays both Della and Jim to be characters with whom the reader can identify and empathize.
Della comes across as young and impetuous. Her bold and quick decision to cut her hair reveals her to be hasty at making decisions.
Later, as she waits for Jim to return and prays that he will still find her attractive, the reader also finds that Della is eager to please and vulnerable. She is loving, kind, and incredibly unselfish to give up her most valuable possession.
The reader sees less of Jim, since he only makes his debut at the end of the story, but through his reaction to Della's hair and also Della's own thoughts of him, the reader can draw many conclusions about Jim's character. Foremost, the reader knows him to be a kind and loving husband; Della thinks the world of him and would not have sacrificed her hair for him otherwise. O. Henry also portrays Jim as being hard-working to make ends meet for his family. The young man is tired and stressed with worry about providing for his young bride. The detail that he has no gloves in the winter reveals that he too is unselfish, putting off his own comfort in order to help Della more, and of course, the sale of his valuable, heirloom watch shows that he is truly unselfish as well.