The question asks for an analysis of a character's thoughts within a piece of literature, and what these thoughts reveal about his relationship with another character.
The question regarding why Will has Random Thought No. 2 and what it reveals about his attitude toward Uncle Mark appears to be discussing character development and relationships within a literary work, making it relevant to an English Literature class in high school.
The student's question is not referring to a specific text, making it difficult to provide a direct answer. However, generally, such thoughts can indicate nuances in the character's relationship, possibly showing conflict, estrangement, or ambivalence.
Looking at a question dealing with a specific character's thoughts or attitude like this reveals a lot about interpersonal dynamics within the narrative, drawing attention to potential themes of the story.
Unfortunately, without the specific context of the text in which Will and Uncle Mark are characters, more precise insights cannot be provided.