This was a demonstration of using Bitcoin on Lightning Network ⚡ for a retail / Point of Sale (POS) transaction. This occurred during the Bitcoin 2021 conference in Miami last week.
The demonstration shows the "customer" scanning a QR code from the cashier's tablet, and paying the Lightning network (LN) invoice.
The customer didn't hold bitcoin. The wallet app (Lastbit) paid the LN invoice using the customer's bank debit card (on file with Lastbit).
The merchant in this instance was also using Lastbit, and in this case, the proceeds of the sale (bitcoin on Lightning network) are converted to dollars on arrival (which is an option available to the merchant).
The merchant doesn't need to use Lastbit. They could be using a self-hosted BTCPay Server, for instance, and never touch dollars. But to show how LN can work well for retail payments, the merchant in this instance is receiving payment in fiat -- which many merchants choose to do (for now, until their vendors, employees, etc. also accept bitcoin).
Source: Tweet by LastBit.
