Private Assets
From unroole CMS wiki
For more information, see Assets.
Assets in the system can be shared eithier privately or publicly. Privately shared assets are only accessible from the admin panel or when added as content through other panels (ex: Layout Editor). This means that sharing or bookmarking a link to these assets will not work. If this functionality is required an asset should be changed to public which gives full access to share the asset outside of the CMS.