This one has bugged me for a while. Seems like a disconnect between the software and the planning of the self-checkout terminal. Here’s what happens:
You scan in your items
You choose to pay (by card)
You are asked to insert your card, so you move to the card reader and gaze at it…
Meanwhile, the main display is asking you a question about cashback, which you don’t notice because you are staring at the card reader and waiting to enter your pin!
It could have been better designed by either having the card reader close to the main display, or having the question about cashback coming up before you are asked to enter your card (which makes more sense anyway).