Dropbox has become the first 3rd party storage company to deliver an app for the Xbox One. The UWP app is available for Windows 10, Windows 10 Mobile and now the Xbox One. This means you should be able to view your media files stored in the cloud on your Xbox.
There is an adapted UI design for the TV and the app supports the Xbox’s gamepad and Xbox One media remote, you can view your pictures and videos directly in the app. You can also share files, comment and upload new files.
You can find the link in the Windows Store.