Are you sure that? My memory is hazy but I think you parked the shopping cart at the register instead of behind it and just moved your items from the end of the belt back into your shopping cart while they typed in the codes without picking up anything. I think I even remember that customers were a bit confused that they needed to move their carts behind the register which was solved by signs and floor markings.

And interestingly they were not any slower.

my mother still says they were much faster.

But I think Aldi had a smaller varierty of products back in those days too.