Revealing mistake: When Lucy first meets Mr Tumnus, she looks down at his legs and sees that they are not the legs of a human, but of a fawn. During this shot, Tumnus shifts his legs slightly, and it is evident that the CG legs do not exert any pressure on the snow at all. This mistake occurs at several other points in the film. (00:15:20)
Revealing mistake: When the Beavers and the Penvesies trek along the ice river, the Beavers drag their tails along through the snow, yet the snow is never disturbed by them. (01:03:35)
Revealing mistake: Aslan is carrying Lucy and Susan on his back to the battle and is running at a very fast speed. If you look at the girls' hair though, it isn't moving at all, flat against their backs as if there wasn't any wind. (01:51:20)
Revealing mistake: During the battle scene, the White Witch clearly stabs Peter in the arm with her sword. In the very next shot the sword goes through the chainmail behind his arm, into the ground. (02:02:40)
Revealing mistake: When the girls are on Aslan's back, you can tell that there is a flat screen behind them.
Revealing mistake: When the stone tablet breaks, Lucy and Susan fall down. But if you watch the ground, it never actually moves to make them fall.
Revealing mistake: During the final battle a harness is shown on the water buffalo soldier as the main centaur attacks and kills him (the harness is visible as the soldier is hoisted into the air).
Answer: It was never mentioned in the book or the movie that breath wasn't visible, so it is a mistake.
Phixius ★