Remote Control (often called Shadowing) of a user session on Remote Desktop Services (RDS) is a technique to interact with the user session. This allows for example a helpdesk to helpout an enduser with a questionor issue. Remote Control can be disabled in several places using GPO, manual settings within the RDP-tcp properties or even on the user properties in Active Directory.
You can use the following WMI command to check the Remote Control Settings:
get-wmiobject -namespace "root\cimv2\terminalservices" -class Win32_TSRemoteControlSettingTake a look at the output properties Levelofcontrol, PolicySourceLevelOfControl and RemoteControlPolicy.