The bug:

Rotating elements in entities are shaded incorrectly. This can be easily observed in:

1. The player's head when it moves around;
2. Panda heads while they're sitting;
3. Lazy pandas while they're laying;
4. Shulkers when they're not standing upwards;
5. Villagers when they're sleeping;
6. Any mob when it's looking up;
7. Armor Stand arms in certain poses;
8. Ravager's different body parts;
9. 2D projectiles (they behave similarly to the player's head).

Screenshots/Videos attached: Yes

Notes: This is an issue with Render Dragon, and it's one of the only things that differ visually from the old rendering engine.