The fire from the guard pigs' torch is shown even when the pigs should cover it. I've drawn circles on the third picture illustrating that.
Edit: I would like to add that it also shows the same thing with the player holding the torch; the fire is visible through the player when facing away from the screen.
Find a pig village. When night falls, watch as the guards take out their torches. Rotate the screen (Q and E) and observe how the fire is visible through the guards.