Here's why:
* Personification is giving human qualities to inanimate objects or abstract concepts.
* In the scenario, the grade-giver is described as "speaking". While a grade-giver is a person, it's the *grade* itself that is being personified. The grade is given human-like action of "speaking", implying it has the ability to communicate its message to Shawn.
The sentence suggests that the grade itself is a voice that conveys the desired message to Shawn, making the grade a more active participant in the story.