The Definition of Done (DOD) is directly connected with the Product Backlog Item (PBI) and the Sprint tasks; in short, what you deliver based on the teacher’s requirements.
This exercise is designed to understand the teacher’s requirements and deliver an incremental value after each Sprint.
In the way we implement Agile, the teachers play the role of the client. The teacher and the client’s main difference is that the client discovers what he wants when he starts to see the product result. However, the teacher knows what you have to learn; then, she can place the proper requirements to let you create the lesson’s content.