Answer:
Dramatic irony.
Step-by-step explanation:
If the author had made the reader aware of the gift that Jim had purchased at the beginning of the story, this would be an example of dramatic irony. Dramatic irony occurs when an audience has a deeper understanding of the events of the story than the characters. When this happens, the words and actions of the characters have a different meaning for the audience than for the characters. In this case, if the audience had known about Jim's decision, they would have known it was a bad one, while Jim continued to believe it was a good one. Hope this helps!