This policy setting turns off Windows SideShow. If you enable this policy setting, the Windows SideShow Control Panel will ...

This policy setting turns off Windows SideShow.

If you enable this policy setting, the Windows SideShow Control Panel will be disabled and data from Windows SideShow-compatible gadgets (applications) will not be sent to connected devices. 

If you disable or do not configure this policy setting, Windows SideShow is on by default.