Notification method and notification system

A notification system, comprising:

• a display device;
• a camera;
• and
• an information processing device,
• wherein the information processing device executes a notification method including
• a first acquisition step of acquiring a first image captured by a camera at a first timing, the first image including a display area of a video displayed by a display device,
• a second acquisition step of acquiring a second image captured by the camera at a second timing after a predetermined period from the first timing, the second image including the display area,
• a comparison step of comparing first analysis data based on the first image with second analysis data based on the second image,
• a first determination step of determining, on a basis of a comparison result in the comparison step, whether or not a first deviation has occurred, the first deviation being a deviation of a display parameter related to display by the display device, and whether or not a second deviation has occurred, the second deviation being a deviation of a photographing parameter related to photographing by the camera, and
• a notification step of notifying a user of deviation information indicating a deviation determined to have occurred in the first determination step among the first deviation and the second deviation.