That first photo (upper left) looks more like the SAS-51 (longer nose than the Aerostat). Foreshortening (Foreshortening refers to the visual effect or optical illusion that an object or distance is shorter than it actually is because it is angled toward the viewer.), could make the airship appear more "square" (like the Aerostat) at certain angles.
Also, I reviewed the last video of the SAS-51, and at certain angles you only view 3 of the 4 fins.
Finally, it does appear untethered to me. From your description of its movements, you did not believe it was tethered.
Do you recall precisely what the Isreali papers said about the aerial surveillance of Bush's visit?