Moroccan Islamists disapproved of her short dress, so they beat and stripped her

From Bikya Masr:

Women’s rights in Morocco have come under the spotlight recently after a young woman was assaulted in a Rabat market by people she called “Salafists,” or ultra-conservative Islamists. She said she was accosted by the men because of the short dress she was wearing.

Other witnesses were reported by the Magharebia news portal as saying the girl was attacked with stones and beaten after the assailants said the dress was “too revealing.”

Human rights and women’s organizations issued statements denouncing the assault on the Moroccan girl, during which she was stripped of her clothes entirely, reports indicated.

Young Moroccan men and women turned to Facebook and online groups to call for protection of individual freedoms in Morocco, including the group “Débardeur and I am fine.”

“Though this incident appeared in the media and gained wider attention, that does not mean it is not repeated on an almost regular or semi-daily basis in all the alleys and streets of our cities. It may not end in stripping the girl of her clothing, but the verbal and physical harassment that women may experience is sometimes more heinous and horrible,” said Nora Al-Fuari, an activist journalist at the Al-Sabah daily and a member of the Facebook group.

I don't quite get how stripping a girl is more modest than her wearing a dress, nor how beating a girl is less offensive than her wearing a skirt that reveals her shins.