The photography is nice, but I have to say I have some doubts about how real this it. First, the notion of someone just falling asleep while they're tied in a chair waiting to be tickled is a little bizarre. Even someone worn out from partying would have trouble doing that, and supposedly Susan (the model) HATES being tickled and does it only for the money.
Second, look at some of the pictures later in the series, in which Susan is tied to the bed. Even when she's evidently screaming with laughter, and according to the captions was struggling wildly, the ropes tying her ankles to the corners remain slack. What's up with that?