I find the principle behind these cards fascinating – and the one on the photo most beautiful!
And then I even found an instruction!
At the next opportunity I want, too! ;-))
Links:
Foldover card in all phases of opening:
Instruction (Barnyard Foldover Layer Card)
see also E66 0° card and E66 0° card opened up
The first card of this kind that I saw was Poetic Series #38 WorkName : Hide-and-go-seek (search there for ‘Poetic Series’ => card number 38 with the name of ‘Hide-and-go-seek’)