I also think whitetrue means the ability to add several covers and screenshots to one game.
The site´s main purpose is the collecting aspect of gaming, to highlight the differences between the versions of a game and to show
the collections of the members as exact as possible. If you got an different cover for a game that is not already in the database, you make a new entry and upload the picture.
To add screenshots for games would only make sense, in my opinion, when it shows a version difference thats not already visible on the cover or package.