Toward the middle of the second paragraph, the comparison between the stars and a distant cloud of fireflies" (sentence 6) is best described as

E. a lively metaphor that emphasizes the narrator’s initial delight at being able to see stars in the city

Explanation:

"Wonderful stars, a distant cloud of fireflies: but I felt in my body what my eyes could not grasp, which was that their true nature was the persisting visual echo of something that was already in the past."

Fun is also a verb.