Summary:
When you're in the inventory of a horse, donkey, mule, or llama, the mob's model itself stays still instead of looking at the controller pointer, but not your mouse cursor.

Repro Steps:

1. Open horse's inventory.
2. Move your controller pointer.
3. If you have a mouse, use the mouse to move around in the inventory.
4. Observe and compare the results.

Observed Results:
The horse model does not look at your controller pointer at all.

Expected Results:
The horse model should look at the controller pointer instead of staying still.