You know, just Missy annoying the hell out of Clara.
It’s one of those moments where she’s probably simultaneously annoying the hell out of Clara and checking the resonance of the walls for weak spots.
but we can all agree that it’s highly unlikely that Clara sat down next
to the Mistress. So basically Clara must have been sitting there first
and Missy at some point came to her, sat down and started doing that.New
level of the Master Is A Fucking Cat: Walking up to the person that
likes you the least and delight them with your presence.