If you don't attach an image of the advertisement, it's hard to answer your question. If I had to guess what sort of ad you were looking at, though, I'd guess most likely it promotes a labor-saving device. That was a huge emphasis of household tools and gadgets marketed during the postwar wave of consumerism.
Oh, and the answer is definitely NOT that it encourages women to work outside the home. During wartime years, the USA depended on women in the workplace to aid the war effort. But after the war, there was much pressure for them to go back home and resume the role of the stereotypical housewife.