1. A method to perform inventory display auditing, the method comprising: overlaying a reference image over a current image displayed on a camera display, the reference image corresponding to an inventory display to be audited; comparing the reference image and the current image to determine whether the current image and the reference image correspond to a same scene; and when the reference image and the current image are determined to correspond to the same scene, indicating a difference region in the current image displayed on the camera display, the difference region being a first region of the current image that differs from a corresponding first region of the reference image.