Mise en scene refers to everything presented in a scene that appears in front of the camera, including location, costumes, props, and color. The document provides details on the mise en scene for a music video, including using a house to show a relationship and hill to represent lyrics, not using costumes for stick figure characters, including a guitar as a prop to connect to song lyrics, and using bright colors for happy scenes and cool colors for sad scenes to quickly portray character moods.