You probably know that during WWII, when many men were drafted or enlisted in the military, there was a shortage of labor needed to support the military; and in this shortage, women were called into a service too, many more, to fill labor demand. As to the posture, this from Wikipedia,
The poster was very little seen during World War II. It was rediscovered in the early 1980s and widely reproduced in many forms, often called "We Can Do It!" but also called "Rosie the Riveter" after the iconic figure of a strong female war production worker. The "We Can Do It!" image was used to promote feminism and other political issues beginning in the 1980sSo thinking myself of the association to the war (effort); in fact, the posture is apparently associated with feminism and the whole sense of entitlement and equality, foremost for feminism. Can they do it, have they done it--or will they in time--is a question from one who does not really understand this movement (because I am not part of it or have no interest...); yet, it is a part of me, us and them. Yes, feminism is a movement that affects us all whether accepted or acknowledged. As human behavior however, none dare or desire to be equal; that when they speak or act for equality what they are aiming for is, always, power over others regardless of what is best for the commons, community and culture. Equality is finally, in a personal or public way, not a reality.