There's a difference between deriding the physical appearance of somebody who can't help the way they look, and deriding the physical appearance of somebody who apparently doesn't care how they look.
This bishopess falls into the latter category. Her lack of care for her personal appearance indicates a lack of self respect and decency.
I would also add that people who buy into the sad and un- Christian "doctrine of total depravity" might have a tendency to not take care of themselves.