What purpose does design serve?

When dealing with money design is essential. It ensures you are; using the correct services, despencing the right dominations, following the correct processes and aids precise counting. Colour, size and even texture all help inform all those decisions. With the advent of digital money there are fewer ways to help inform those decisions.

Look at the three #qrcodes above. You might think that choosing one design might just be up to personal preference. You'd be wrong.

1. Your just about to pay the barman in a packed nightclub in Ibiza at 2am. The music is thumping. The bar is three deep. Your enjoying your self.
2. You have just got of the back of a motorbike after a 45min ride to get to work on the out skirts of New Delhi, the streets are packed, your being jostled from every direction, noise is everywhere, the driving is shouting at you just to be heard and shoves a phone under your nose with a qr code on it.

In those situations which of the following designs goes as far as possible to remove ambiguity and make sure people are paying with what they think is the correct currency?

Well? Which one do you think it is and why?