Final answer:
The detail the speaker in the passage would have changed at the end of the scene that took place over two decades ago is the feeling of loss and longing for the past.
Step-by-step explanation:
The detail that the speaker would have changed at the end of the scene that took place over two decades ago is the feeling of loss and longing for the past. In the passage, the speaker reminisces about the beautiful moments and relationships that are no longer present in their life. They long for the past and wish they could go back to those joyful and nostalgic times.
The speaker describes the waters lapping on Sherry Island, the moonlit veranda, and the gold color of their loved one's neck's soft down. These vivid descriptions create a sense of longing and fill the speaker with grief for the things that no longer exist. The speaker realizes that they can never go back to the past and must accept the gray beauty of the present.
This detail reflects the theme of impermanence and the passage of time. It highlights the speaker's emotional journey and their realization that the past is gone and cannot be changed.