Project and Practices in Physics (P-Cubed) is a flipped section of introductory, calculus-based physics, which is designed with a problem-based learning approach where students work in groups on complex physics problems. Learning Assistants (LAs) are critical to the course, where they each function as a primary instructor for four to eight students by asking questions and prompting discussion during class. LAs in P-Cubed also write individualized weekly feedback to each of their students, which is meant to offer suggestions to the student for how to improve their work in class and provide the student with a justification for their in-class grade. We conducted semi-structured interviews with LAs to examine the ways that they construct feedback and how this impacts their own experiences as students taking classes. In this paper, we examine and discuss the reflections of one such LA as a case study for the impact feedback can have.