@rebane2001 It's a clever idea still!

Kind of related to what I've seen in some CTFs where you had to manually decode a broken QR code.

@rebane2001 Simple: QR codes have certain amount of redundancy for error correction.

The idea of this particular QR code is that it is deliberately invalid unless if you cover the invalid part (the finger area). When you do that, the remaining error correction parts make the code valid and readable.

Clever, but nothing exceptional.