Sharon Horgan's laugh...
...is annoying. It's a sort of half-laugh to indicate amusement, which thereby drains the amusement out of the incident she's partially amused by.
Note to the BBC; yes, HIGNFY could use more female guests and certainly more presenters - but they need to be funny. Why not try Rebecca Front as presenter? She's been an ok guest in the past. Or, sticking to a "The Thick of It" theme, why not the actress who plays Terry?