A bounding box or bounding rectangle is an invisible diamond that the game creates when agents are injected into the world. It allows the game to get a sense of the size of an agent, using the first image in the c16 sprite file to do so. A common spriting error is to create sprites of slightly different dimensions, or make your agent take a different POSE where the new sprite has different dimensions (e.g. carrots going from upright to laying down) resulting in a "bounding box error". This can be resolved by making sure your sprites are of exactly the same dimensions.