A ghost frame is a feature used primarily in broadcast and autocue applications. It allows the screen to simultaneously display two different versions of an image — one visible to the human eye and one that is invisible to the naked eye but correctly exposed for a camera pointed at the screen.
A common use case is an autocue: the presenter sees the text overlay on the screen, but the camera sees the clean background image without it. Multiple ghost frames can be layered on a single screen. It is worth noting that the inclusion of ghost frames can introduce a perceptible flicker to the image as seen by the human eye, which may be acceptable in some broadcast contexts but should be considered carefully for live audience applications.