Every time a piece of media is newly uploaded in Media Manager, the end user will be notified on the app via the What's New button. This information will come through when the app has been updated, either automatically or via the "Check for Updates" button on the Settings page. The What's New tab at the top will display the number of new files via a badge number.
When you access the area, the files will be displayed. Once you have viewed the new pieces, you can push the "Mark as Seen" button in the top right, this will remove the badge numbers from the icon.
As the account administrator adds new content to the app, the new media will populate in the What's New section.