It adds to the surprise created later when it's revealed that Jimmy did meet Silky Bob; indeed, Bob is saying these words to Jimmy himself.
Explanation:
Foreshadowing is a signal of what comes next in a story. In the excerpt from "After Twenty Years," the author O. Henry makes use of foreshadowing to provide readers a hint of what will occur later. In fact, Bob does not recognize Jimmy as a policeman, and at the end of the story he finds out that Jimmy was actually talking to him before he was arrested. The reason is Jimmy did not want to apprehend his friend.
The one that does not have a strong influence on the American English in the Late Modern English period was A. Separation from England. Late Modern English is from 1800-present. The changes in vocabulary in this time was due to industrial revolution as well as scientific advancements and colonialism as well.