When you look at something "pointedly," you look will say something in addition to his words.
For example, I might say something about how nice the "scenery" is (the view, how pretty things look) while looking "pointedly" at a very good looking guy, as my way of saying "and it's full of good looking guys, too." Or I can say it sarcastically, and say "And the buffet is full of healthy choices" while looking pointedly at the desserts.
I imagine the skirt is rather short and shows off a lot of her legs, so he finds the "beauty" of the gown to be how much of the woman it exposes.
Student or Learner