Unless I am completely missing the genius of this I think that this is trash.
The item in question: Castlemaynia. By the one and only Andrew Mayne. The point of a card castle is not to look like a glued up piece of junk, but rather like a fragile construction. So the impossibility (magic) is, that it cannot be done that quickly.
Mayne seems to be proud of this item, as his website shows (second from the bottom). Why?
I do not know, but I feel that this guy is kind of erratic with his quality output, that it leaves me wondering.
I am not saying Mayne is a bad magician, but he sure puts out bad magic for sale, making him this Week's Magic Failure.