Can't mirror display properly

[aviavi]

Originally Posted by ThePhantom

?
Mirror is mirror. In short, it's constrained to the dimensions of the host's display. What behavior are you expecting (some type of stretch mode?)

I was expecting the same mirror behavior that happens when I plug in the same external display to the Thunderbolt port: Full screen.

Originally Posted by ThePhantom

?You'd be better off extending the desktop to the external display.

The problem with extending (or arrangement mode)this is that the mouse cursor and Finder/Application windows can be moved off screen (onto the laptop screen), even with the Macbook lid closed. If I wanted to use Macbook and external display, this would be fine.

Originally Posted by ThePhantom

?What generation of MBA do you have?

It's a 2012, so it has USB 3.0.