At the supermarket check out somewhere in Germany. Cashier to customers: “28,35 Euro”. The customers silently passes the 50 Euro bill to the cashier. “21,65 is your change”. The customer packs up his groceries and leaves the store.
This type of limited conversation at the supermarket check out is not a rarity. Until a couple of years ago this was a common interaction. Nowadays, you will get a “good day” or “have a nice day” from the cashier before he puts the groceries in your shopping cart to make space for the next customer.
However, the cashier would never ask the flour- and sugar-buying customer if they are going to bake today. Furthermore, if a customer buys cereal and milk the cashier would never ask, with a winky face, if they are someone that likes breakfast for dinner. The cashier would also not say how much he likes cookies if someone was buying some. The check out is a place where you pay, not for small talk.