You have to spread the cubase window across both screens. Then you can shrink the project window to fit in one and pull the plugins on the other
First your computer has to have that option... otherwise it is a mimic of the original image.
Check your video card setup in Control Panel (on a PC, don't know on a Mac.)
Pete
Why would you have two screens with the same image????
Tried that on the mixer... didn't work. Now I am pissed and need to figure it out!!!