It learns one teacher's marking standard, grades a student essay the same way, and shows the exact lines behind every score.
Each highlight is a line the grader cited — hover a margin note to find its evidence in the essay.
Not about the essay above — this is the teacher's marking standard, learned once from essays they scored on this one assignment. Every essay is graded against it, as an answer to that task: the standard is teacher-and-task specific by design.
Two questions, measured apart. Did it match the teacher's marks? And when it was wrong, was it a fixable pattern or just noise? These are from the held-out evaluation — not this one essay.