I htink this poem nails it! Older women have experienced much more, have more fully and deeply entered into, and can thus more fully and deeply express true womanhood, through their carriage, their eyes, their movements, their emotions, their choice of attire. And I find the full flower of womanhood, in full living expression much more beautiful, there is so much more there to intrigue and to captivate a person than a young woman can possibly have. The young are indeed beautiful, they simply aren't fully women yet. My two cents, anyway.
I guess i agree with those three about this poem. In my limited understanding of how to analyze what poetry means, it does seem that all whitman is saying is that even though young women are very attractive, older women have more to offer. Since the older women have more experiences that is probably what whitman is looking at, not neccessarily their looks.