I'm gonna throw another possibility out here, that it IS a physical model, but that it is MUCH smaller than indicated in the still. If it were a foreground miniature that was less than perfectly executed, that would convey the subtle wrongness of the pic. Abrams actually did a foreground miniature for the first film, but it was a scene cut from the release print (interesting synchroncity, that!), so they do, surprisingly enough, actually know the process.
Trek used FG miniatures in TMP for Vulcan (the brief shot at Yellowstone) and for Starfleet Command in TWOK (most of the lobby - lower level & atrium overhead - where Kirk & Spock wait for the elevator.)