I took this in Hedge End M&S when they had their one day only 20% spectacular. way in the distance, you can see the large 'pay here' sign. Believe it or not, this queue is for that set of tills.
It goes through the store until level with the far end of the tills, then towards the tills for a bit, before doing a post office queue style zigzag a couple of times.
This was repeated throughout the store, and parking was a nightmare.