Here's why:
* Mood in grammar refers to the grammatical category that expresses the speaker's attitude towards the proposition expressed by the verb.
* The sentence is suggesting that analyzing the mood of a writer's verbs can reveal insights about their writing style, their emotional state, or their intended impact on the reader.
While "writer" and "verbs" are also important words in the sentence, they are not inherently academic terms in the same way that "mood" is.