Another thing: I'm guessing they don't have paid staff to bag groceries for customers like many US stores, but what they may have that's common in Europe but unknown in the US: the boat-tiller-like divider in the conveyor belt space past the cashier. Customer A's things get rung up and continue to side A. When done with customer A, the cashier shoves the divider across so the belt now takes customer B's stuff to side…
Our local WinCo, a US West Coast chain, utilizes checkout dividers to great effect (and employs some of the other cost saving measures mentioned in this article). People aren't nearly familiar enough with using them, though, they park their cart alongside the conveyor belt blocking the next customer instead of going to the end of the conveyor to bag their groceries. An efficient cashier can move faster than two slow customer bagging groceries, some of the local cashiers will have three customers bagging at once.