Magicians: catch what Derren says at 3:55-4:00. It’s total cheek. Magicians will hear Derren say, if they listen very carefully, exactly how the trick is done. Derren says the name of a trick that’s known to all magicians. He’s winking at magicians and saying, “See–I can take that old trick and dress it up so that you can barely recognize it.”
And the rest of us can just enjoy watching a magician who can take a standard effect and make a performance piece out of it. It’s what makes Derren Brown so watchable.