I would imagine it is because of it being an airborne IFV. So it needs to cut down on weight hence, the simple turret structure and hatches. Also it‘s a prototype, there might be changes.
Yes, a normal mortar is a tube with a fixed pin on the bottom... a primitive yet highly effective weapon. This is simply a moderately armoured vehicle to bring the same capability in a self propelled and mobile form.
The vehicle is old Mengshi I This is mortar carrier to provide fire support for either Airborne troop or light armor troop. Traditionally airborne troop are provided only with light armament like Machine gun, Light mortar or ATGW not good enough against armor troop. So the trend now is to equipped airborne troop with some heavy caliber 76mm gun or 80mm mortar that is not man portable therefore the need for carrier like Mengshi. But the problem with airborne troop is sooner or later they run out of supply since they normally drop behind enemy line to seize bridges, airport or to prevent flanking movement.
Just want to add...
Thanks for the very informative and educational reply. Appreciate the effort.
It is anything but little, though
But it sure seems like it. You ask these provocative questions here and on the J-20 thread (calling it a 4th generation fighter and using a dubious article to back it up), probably other threads. It absolutely seems like you're trying to pick a fight, so quit it.
Well I'm sorry