Just looking at the three images above I would say the side door behind the truck cabin is only on one side and is wrong in the drawing, but I still get the impression that the area behind the cabin for electronics and crew is slightly larger in the new vehicle.
Actually Pantsir have doors on both sides for crew, that they could be quicker inside or outside.
Of course they are currently putting the new naval version into service... perhaps this is testing of that system?
I also think this could be a testbed for a new radar, because this radar was never seen before. I doubt this radar could be serial one for foreign customer. It will be interesting to see if this radar will be part of new Pantsir modification or it is for a new SAM system and this Pantsir is only testing platform. It will be also interesting to see if this radar is in any correlation with new naval version.
It should have much better performance against low flying and small RCS targets and its continuous 360 degree coverage will make it much harder to sneak up on or hit.
I think here could be the answer, why there could be on top left and bottom right of main radar antenna RWR detectors. Maybe those RWR detectors could detect AESA radar on longer distance than radar could detect stealth plane. Radar could also compare datas from both sensors and if there is a bee using AESA radar, than this could be F-22 or F-35.
It seems on the photo, that there are at least two more Pantsirs around this one, but we could not see, what type of search radar they have.