Is Derren Brown Bluffing?

Hi, ok i know no one knows for sure but I was wondering when Derren Brown tells you "how he did it" is he lying, as surely it cant be as easy as that, for example, last week when he "made" that girl choose a giraffe out of all the toys in the toyshop, did he really do that with a few giraffe shapes, patterns and pictures hanging about and sneaking the word giraffe into conversation a few times? What do you think? Im not convinced!