One eloquent answer to the question in the title was provided by a woman friend: "If society, and men in particular, valued women more in terms of intelligence, kindness, abilities, and talents, obsessive selfie-posting would vanish."
I understand her point, although absent a change in how women are valued, the vanishing has yet to be proven. Responses tend not to be quite as automatic and uniform as my friend thinks.
Now, I understand perfectly well that our society puts a premium on a particular set of fashionable female looks. These have varied from age to age, from Rubenesque to Twiggy. There isn't one objective standard of female beauty, or of beauty in general.
When a woman's body fits the recipe of the day, it results in male attention (wanted and unwanted), sometimes jobs, and other benefits. The "uglies" are shunted aside.
None of this is new to me. I was first exposed to feminism in 1972 by a very good woman I was dating,, who inspired me to read most of the feminist canon of the day.
The result was that I felt quite guilty. My girlfriend Doreen was, to me, akin to Russian revolutionary Alexandra Kollontai calling to my attention that I had been trained to be a Tsarist officer, in other words, a man trained to be a male chauvinist, even if I didn't realize it. It's not something you just shuck off easily.
Over the years, however, the childhood "womenist" stance I adopted when my father abandoned my mother and me, flourished with Doreen and further experiences into a well-founded ingrained intellectual attitude that I would describe as "feminist" from a somewhat reformed man. Certainly, I recognize the importance of abortion rights and equal pay as public planks that must be a prominent part of any progressive agenda. Also, I recognize that certain customs concerning women, including especially body over brain, need to change.
This is precisely why I find the obsessive selfies appalling! It's a step backward.
A young woman may be unable to change human history, but she can change her own life. As a Hispanic of Argentine origin, who has lived in both the USA and Argentina, I know perfectly well about being told to be someone that society wants and choosing my own path.
The desire to be beautiful as society wants is a skewed idea. Just as the desire to be successful the way society wants. What is beauty and success other than a social convention? At a defined point in adolescence and youth, each of us has the challenge of deciding for ourselves. This is a reasonable challenge, it's about becoming truly your own person.
A young woman may be unable to change customs that come down from millennia, but she can change her own life.
There is a lot to be changed in society and I think feminism is doing a good job of identifying some of the things that most concern women. There's a conservative and regressive pull right now that must be fought by all. It's not just a war against women, it's a war against the 99%. We have to hold fast on these issues.
The idea of getting validation, or social acceptance, is a foolhardy goal. In my more devoutly religious days, I thought God was the only one whose acceptance I needed. The Quakers have a less religious view in seeing the spirit of God and Her wondrous love in the hearts of each one of us, regardless of creed.
Let women, young and older, seek their own heart's acceptance above all. Toss out the cosmetics (even the antiperspirants)! Dress for yourself, without regard to fashion. In the same vein, men need to cultivate their inner selves by crying when needed, by accepting vulnerability, by declining to be money machines. No more fake stoicism, going to war and brawls and running the rat race.