how can someone sell something that doesn't belong to them? I don't get it. like this guy getting 1 million dollars offers for a QR code pointing to the first b

how can someone sell something that doesn't belong to them? I don't get it. like this guy getting 1 million dollars offers for a QR code pointing to the first bitcoin transaction[0]? 0:https://opensea.io/assets/0x495f947276749ce646f68ac8c248420045cb7b5e/103666867995443681532939841143094496038419332685195661876899823206669416923137 https://opensea.io/assets/0x495f947276749ce646f68ac8c2484200...