It's only a Panther. The flattened chin on the gun mantlet means it's probably a Panther Ausf. G, since it's the first to get fitted with that new mantlet design.
Another reason it's not the E-50 is because the turret isn't a Schmalturm. This one's sporting the 75mm KwK 42 (L/70) that comes standard on your production model Panthers.
Edit: Checked the Artist's Commentary. Confirmed it's a Panther G.
Edit 2: Checking out that "T-34" in the background while I'm at it. That's not the T-34.
The T-34 lacks the rear-facing machinegun ball turret like this one has. The shape of the turret itself is all wrong for the T-34. It is, however, what you would find on a typical IS-2. Re-tagging as such.