It's not a Panzer V "Panther" (Sd. Kfz. 171) but a Panzer VI Ausf. B or "Tiger II" (SdKfz 182), other name "Königstiger" (VK4503). The Panther is a medium tank, with a 75mm KwK 42 L/70 gun for a weight of 44.8 tons. The Tiger II (this tank) is an heavy tank, with a 88mm KwK 43 L/71 gun for a weight of 70 tons.
The Tiger II is a sort of "improved" Panther, with the same sloped armor. That's true, the Tiger had no sloped armor but it's not the same tank.