I guess my point was understood and misunderstood. I cannot define for others the words refined and casual. And I don’t want to. What I was trying to say is a person should look at what she (and he as well) is wearing and see what sort of message it sends to others around them, especially those of the opposite gender. This requires honest introspection. That is a part of tznius as well.
I’m not making a defintion or discussing a long skirt, but trying to explain why some might feel the long skirt or the denim skirt is not appropriate. What message does the clothing convey. And this will differ based on the community. Walking in to Meah Shearim with certain clothing may be flaunting and unrefined, whereas in Flatbush the same clothing might not turn any heads. But it behooves us all to ask ourselves the question of what message I am conveying with my clothing even if it covers me as it should.