He's probably running his dualhead drivers in a mode that exposes just the one large monitor to Windows. Doing this will also break applications like UltraMon so I don't see the point. I had this ...

It used to be that if you wanted to zoom any window on your Mac to see as much of the content inside it as possible, you’d hit OS X’s green button in the upper left of the window. As of OS X Yosemite, ...