Sometimes the background of a picture can be more interesting than its actual subject. That can be especially true with images of pre-production work. In this case, the subject was a full size clay model of the 1979 Ford Mustang. However, in that background is another clay, that appears to be a sedan, and behind that are drawings on the wall of what appear to be a compact multi-purpose vehicle.
To the left of the Mustang proposal (not shown) is yet another full size model that could be the physical representation of one of the drawings on the wall.
In any event, these pictures leave plenty of room for speculation.