I had to buy some non-food items.
When I came up to the counter with my items, the shop assistant stepped back.
When he stepped forward to put them through the till, I stepped back.
When I stepped forward to bag them, he stepped back.
And so on, to-and-fro, to-and-fro, until the transaction was complete. Then our eyes met. Wry smiles. "Thank you. Goodbye" and we parted.
Weird, polite, terribly British. And totally different to the crowded chaos that we're hearing about all the time.