I suspect that Karren's grimacing and disdainful comments in the last programme as she delivered the performance results of the teams is a result of a conscious decision attempt to make a greater impact on the programme and amplify and dramatise her role.
She is aware that she is superfluous to requirements as she doesn't provide insightful comments, intellectual weight or entertainment, so now she has decided that her small role should come with added histrionics and it should deliver some contempt, some vitriol, some praise and an emotional roller coaster narrative as each piece of information she delivers hints at one result, only to be confounded by the next. It is desperate attention-seeking, amateurish stuff. Someone should take a spanking stick to her.