Stopping between repetitions to discuss how it should be done is a bit like retying your belt, cleaning your specs and kicking the mats in, innit. Sometimes it's done because it has to be done, and sometimes it's to have a bit of a break. I find it pretty frustrating when it's a procrastinating strategy, but then again sometimes people take a break because they need a break. I get the feeling it happens when your partner is not confident about what they are doing, and embarrassed about whatever they're doing wrong. It can be a bit like a cry for help, saying "take it easy, give me some support and encouragement here".
Being an insensitive ogre by nature, I don't often see it like that at the time, and so the pounding continues
Yay, I'm the first to say "innit" on this site. Sorry, losing focus now