Based on the replies I have received so far, my own experience, and mostly the lack to replies to the contrary, I am led to believe that this exercise is an illusion. If so, it's a bit disappointing since the instructions say:
"...This game works because we simply put energy into our fingers causing finger joints to open and the fingers to become longer."
I agree with The23rdMan that it is unimportant whether it works since the result is not useful. But I think it IS important if someone's trying to deceive. Personally I don't like being lied to, even if it is for my own good, or to open my mind to possibilities as shakurav suggests. Really, I would prefer that they take this game out, and replace it with another one - something that would give a "Wow!" factor, but not based on trickery. Testimonials just don't "do it" for me, unless I trust the source; I prefer direct experience.
Hartreefoch, you sound like an intelligent person. I am heartened to know that you find the main segments of Qigong are effective. As far as fooling adults, well of course you can, but it's difficult to fool all of them, as Churchill quipped, and I couldn't find any comments about this elsewhere on the web. Regarding legal issues, I know your country has much freedom of speech yet I was under the impression that there were restrictions relating to claims in commercial speech, especially in health care. Okay, I might be the sucker that P.T. Barnum referred to.

All this raises an interesting question: Is is possible that Chunyi has been fooled by his own illusion, or does he know it's only a trick to move us to the next level of exercises? He seems like a genuinely caring person, so I don't like to think he would deceive on purpose. On the other hand it's hard to fool yourself with a simple trick, so I don't know what to make of it.
Anyway...
I've managed to watch the videos and try the exercises. Whew! Chunyi sure has a lot of stamina. I had to do much of this sitting down as it's tiring to stand for so long - one hour plus.
Thanks;
BD