Artistically, the model is absolutely beautiful. The detailing and weathering is superb, and I love the little metal kitchen chair in the corner.
The ammunition posed leaning up is something that real tankers always have kittens about when they see it in dioramas, though. Occasionally, one does sees a round posed leaning on the turret side of a captured tank as you have done, but this was invariably done by the photographer who wanted to show the folks back home the size of the ammunition used by the "captured monster."
However, I gather the premise here is that the crew were interrupted by the advancing Soviets as they were loading ammunition at a supply point. Several rounds are out of their packing cases and are leaning precariously. Ordinarily, the last thing you want is to do is damage a round by letting it topple over, and the steel cartridge cases of late-war German ammo were heavily greased, so they would pick up any dirt they were set on and introduce it into the moving parts of the breach when loaded, another no-no. In US units, a round was supposed to be removed from its container and handed from man to to man until it was safely in its rack in the vehicle. If absolutely necessary, it could be set down sideways on a tarp to keep it clean. It was almost certainly the same in German units.