To aid usability, unused zones, music sources and microphones can be removed from view on a zone-by-zone basis to provide a cleaner interface.
Navigate to Settings>Zones and select the relevant Zone. Scroll down to Visibility for the configuration options:
Here you can select whether the entire Zone is hidden, or any of the inputs not used in that Zone. Anything that is checked will NOT be visible.
In single zone systems, a single Zone view can be presented without any navigation icons on the left of the screen. This is intended to be pinned to the Home Screen which gives a full-screen app feel with no URL bar.
Navigate to Settings>Zones and select the relevant Zone. Scroll to the bottom and click the Open Single Zone Control Panel button. You will be presented with a screen similar to this, containing the visible sources for the single Zone.