The nice thing of the shoes is that they let the feet completely exposed, only with a clear toe ring/loop. It looks like the foot is been hold only by the ankle strap. Check links:
https://docs.google.com/leaf?id=0Bw9exJdrBr9nMmVlZjMyNDktNjcxNS00NWM1LWFlNmItNTgxNjhlZTg0YWRi&hl=en
https://docs.google.com/leaf?id=0Bw9exJdrBr9nYTdlYzRhODQtMTcwNC00ZDg3LTk1NGYtNmZiNTBkZjM5YjJm&hl=en