The student explores whether over time the mood of the artefact can change, subjective to the person's activity. When the person touches the light body swiftly, the excitement level of the light body rises. The touch of the person has to be directly related to the light body, as LUMA is only sensitive where the light body is. The excitement level (arousal) is a variable that continually adjusts over time. This variable is directly used to determine the size of the light body and the speed at which it moves. The excitement level keeps increasing as long as the person touches LUMA swiftly. At a certain moment, the light body has had enough; it needs to calm down. It will retrieve from the interaction and hold still in one place. Only when the person gently caresses the light body will it calm down again. When it reaches a comfortable level, the light body behaves more swiftly again. This implementation also works the other way around. When the light body feels the person is not active enough, and thus the excitement level is low for a longer period of time, it will try to invite the person to engage in a more active play.