I don't want to be sucked into the stupidly obviously answer... believe me ;-)
But it cannot be transparent, as the MacBook screen is a flat surface objects behind may appear slightly out of place (because of the thickness), but the only way the iMac would would appear to be at a different angle than the real thing is if the screen was not a flat surface. As you can see the bottom edge of the iMac on the is a straight line, but it is not exactly parallel to the real thing.
Also, if it was 'transparent' the brightness through the MacBook would be relative to the current environment, the screen and wall seem light enough, but the metal casing of the iMac is clearly too dark, this would commonly occur when taking a photograph using a digital camera of mobile phone, as the camera thinks its a bright scene and thus reduces exposure to compensate.
So to sum up, it's clearly broken, take it back to your nearest MacTard store
The desktops in the office don't have batteries, but if you unplug them from the UPS, it takes the batteries in that a few minutes to go flat.....the same effect happens