That's a Jagdtiger. A tank destroyer with 128mm main gun, but a gun in a barbette. So the "turret" can't turn which means one shot into the tracks already disables it.
The open engine hatch indicates more damage, but I don't see any penetrating hits. It was probably abandoned and the engine destroyed by its crew.
Most Jagdtiger ended this way. Given up or blown up by their crew after mechanical failure. Their armor was almost impregnable from the front, but when the mechanics fail and you can't keep the front towards the enemy, you're gone.
Wow, thank you so much! That's amazing information. I will add an edit to the post with your comment. Thanks again so cool!
I just realized the "Blende" (no idea what that is in English), the thing that protects the area around the gun, has slid forward. This won't happen unless there's a detonation inside the tank. Whether this was caused by a self-destruction obviously can*t be said. As I don't see any damage around the tank, it probably wasn't an air attack, as falling bombs or rockets would cause visible destruction around the tank.
Also, there's a metal sheet next to it in the one paper. That sheet should be the roof that has been blown out. You can see the rivet holes on it.
So the cause of the destruction can't be identified by me. It was definitely blown up though. Whether through a shell into its left side or self-destruction can't be said. But I guess we can be sure your grandpa would've taken a picture of the penetrating shot if there were one.
Many tanks were also just given up in that stage of the war due to lack of fuel. But at least the front sprocket seems to be blackened which indicates fire, although I don't see any damage on the wheel itself.
You're "Blende" is called a Mantlet in English and I agree with the idea of self destruction.
I agree with your theory that seems very plausible! Such a shame that it was destroyed, but that's the way it goes. I have updated the post, and thank you so much for your contribution! This is the reason why I am sharing these to learn more about them!
Maybe it was a combination of both. A hit to the track then they destroyed the engine. Impossible to tell. Very interesting though.