Blank, dim, and mirror your screens in a multi-monitor setup
Each screen can have its contents mirrored in a window. This is useful for viewing what's on an output device that's turned off or physically located in another room. Right-click on a screen and click "Mirror" to open the screen mirroring window.
When the screen mirroring window is open, you can right-click for options (including making it full screen or adjusting aspect ratio of the image). You can also toggle the blank/revealed state of the mirrored screen.
You can also mirror an arbitrary region of the desktop by clicking the Mirror Region button in the main window or in the notification area icon. This will allow you to mirror part of a screen, such as the video portion of a vertical monitor or a non-fullscreen player.
If a mirror window gets stuck on an inaccessible screen – e.g. if you're trying to use this feature to retrieve something from a monitor that is turned off but somehow the mirroring window also ended up on that same monitor – you can use the "Bring All Mirrors to Current Screen" option. This can be done for all mirrors via the system tray or for a specific monitor's mirrors by using the main window.
This feature has 3 significant limitations to be aware of: