As I've explained before, this works because the QR scanner sees the image in black and white - so light colours disappear. Anything else is covered by the fairly generous error correction.
I'm nowhere nearly as talented as the above artist, but she has inspired me to continue with my Space Invaders QR Code.
It could do with a more game like layout - maybe some high scores and other screen decorations. I'm fairly happy with it as a first pass.