Final answer:
The implicit detail in the passage is that the speaker enjoyed the bookstore, which is inferred from the positive description and nostalgic tone.
Step-by-step explanation:
The detail from the passage "A Poem For My Librarian, Mrs. Long," by Nikki Giovanni that is implicit is that the speaker enjoyed visiting the bookstore. This is implicit because it is not expressly stated but can be inferred from the speaker's nostalgic tone and the positive description of inhaling the wonderful odor of new books. The other details mentioned are explicitly mentioned in the passage.