It looks long, but the main structure of the bustle actually terminates right around the back of the chassis, so there's little actual overhang of heavy structure. The 2 panels on the left & right side of the bustle do suggest a potential autoloader system, with shell & charge taking 1 side each.
What's more interesting is the omission of the fume extractor from the barrel. Does that mean it uses a compressed gas system just like in the French 120mm smoothbore, or it's an unmanned turret so there's no need for fume extractor?