For just the sake of giving this thread no longer reason to exist I am willing to answer the very difficult question, hope it will give answers to all this smart and philosophical talk here.
The answer is very simple actually. While you open the freezer, cold air comes out and air near it starts to cool down, and therefore, vaporized water (which cannot be seen, therefore the thought about mist being vapor is very wrong) will cool down too, it condenses in air and forms a mist which kind can be seen in the mornings...