Hi Sproket, it's odd seeing it with the annexe on cos on mine the door at the side where it's fitted doesn't zip fully out, I guess either the newer ones have a fully removable door panel or maybe it's older ones cos mine is only just over a year old, not sure which.
I just looked on Kampa's website and its the Kampa plus range that you can fit an annexe to, and yes it does have a fully removable zip out door panel, you learn something new on here every day eh.