The visual representation of an item in the format of an image, audio, video, PDF, PowerPoint, or document (Word, Excel) file. The storage utilized for a project is calculated based on the size of the media files uploaded to that project. Shared Shelf automatically creates derivatives for media files to be used throughout the system, (thumbnails, for example, are used in the grid view in the asset panel). Derivatives are not included in the calculation of subscribers’ storage.