She doesn't define it, I think, but it must mean the slapping and choking, like Backdoorman said, and perhaps the face-stomping, too.
That is my point; is she is arbitrarily deciding what is "extreme" and getting back on her pulpit attacking it. It is all relative to each person as to what they consider extreme. Many people in society would consider Lisa Ann getting fucked at the same time by 5 men to be extreme sex, others would not. So who is she to define it for everyone else?
She is such a self absorbed hypocrite.