I am a woman with extremely broad shoulders (and an abnormally high amount of muscle mass, not to mention man-sized extremities). I've sometimes wondered if part of the reason I am the way I am, attitudinally, is due to the kind of hormone configuration that would build my body this way.
But, in any event -- you have to be careful if you're saying "women CEOs have broader shoulders" and then compare it to fictional depictions of people from the pre-photographic past (e.g. portraits). For the longest time, portraits were in many ways symbolic and metaphorical. Features would be highlighted, added, or exaggerated to make a statement. Not to mention the staging of the whole thing.
Think about that famous painting of the scarily-dressed, hook-nosed man and the pregnant woman. It is a painting depicting a wedding, and yet the woman is comically pregnant. I've read quite a bit about this painting, tho its name escapes me -- and everything seems to argue that not only is her pregnancy purely symbolic (fruitful), but so is much of the rest of the setting. It is notable also because there is a convex mirror behind them, showing their backs and the room. The bit of art criticism I was reading, about mirrors, made the case that even the mirror was symbolic of the past.
My point was that certain traits are highlighted and exaggerated for a reason, broad shoulders in men and women were seen as commanding. This meant that their attire exaggerated this in their courts, IIRC it was common for visiting Kings or Queens to wear less dramatic attire when the purpose was alliance seeking and wore more dramatic attire when the purpose was to be threatening.
Modern CEO's and Presidents don't display this type of showmanship in their attire, however take a look at Presidential portraits and portraits of the First Ladies, they still strike the artificial poses displaying broad shoulders.
It would take you an exceptionally long time to find a successful political figure in a posture that doesn't make them look commanding. They're actually trained to hold certain postures and frequently have personal gym instructors to help improve posture, this got leaked about President Sarkozy in France as he was mildly overweight, causing him to change to more comfortable postures in long meetings and speeches, etc.
People take posture to be quite trivial, but the amount of time spent on it by our societies elite really shows how important it is. I can't remember where I read it, but it can supposedly boost approval ratings by ~10% for presidents.
But, in any event -- you have to be careful if you're saying "women CEOs have broader shoulders" and then compare it to fictional depictions of people from the pre-photographic past (e.g. portraits). For the longest time, portraits were in many ways symbolic and metaphorical. Features would be highlighted, added, or exaggerated to make a statement. Not to mention the staging of the whole thing.
Think about that famous painting of the scarily-dressed, hook-nosed man and the pregnant woman. It is a painting depicting a wedding, and yet the woman is comically pregnant. I've read quite a bit about this painting, tho its name escapes me -- and everything seems to argue that not only is her pregnancy purely symbolic (fruitful), but so is much of the rest of the setting. It is notable also because there is a convex mirror behind them, showing their backs and the room. The bit of art criticism I was reading, about mirrors, made the case that even the mirror was symbolic of the past.