Because I don't review everything between changes, there might be 10 small commits I review and state I am happy with, then I might prompt the agent to perform some small refactors after the review, I don't want the diff to show me everything in those 10 commits again in the diff ( like the usual PR would ) I want it only to show me new stuff.
That would be pair programming with extra steps if you're just reviewing updates and not the whole patch that is going to be merged (and which is stamped with your approval).
Not sure if it's just my age but pair programming seems to have a different meaning these days.
It used to mean that two developers would literally sit next to each other, one would type and one would review as the person typed, then they would repeat.
I guess in the world of remote working it's just not practical any more.
I certainly wouldn't call, one person reviewing another persons code during the merge process pair programming at all.