Any time there can be multiple media types displayed at once on the dashboard, you can apply a filter so that only selected media types are displayed. This can be helpful if you want to browse through just your collections, or just your videos.
You will find the filter option in the upper-right corner. This will appear while in the Content View of all projects, or while viewing a specific project. You will also see it in search results.
When you deselect a media type, it will remove those from view.