I just got back from a plane trip where I took my laptop. When I plugged it into the larger monitor I have on my desk. The monitor works fine and has wallpaper AND icons but the laptop shows wallpaper only which means I can't use it on another trip.
It looks like you have changed the primary monitor to the external and set the internal screen as extra desktop space. You will need to go to the "Control Panel" and change how you have defined the two screens.
If you want the same image on both screens then you should select the "clone" setting. You probably have an Intel chipset so you want to select the "intel" icon to change these settings.