The reason I tagged this as a 'racist ad' is because in the time in which it ran, African American women were nearly always portrayed in advertising as maids -- never as dignified homemakers, teachers, nurses or any of the other female roles that were unofficially reserved for white women.
This ad, taken in the context of its day -- which I would guess is the 1940s or early 1950s -- is unmistakably portraying a Scotswoman. Although the stereotype of the cheap Scotsman isn't as widely known in the US today, going back a few decades it was an ethnic stereotype that was used freely, often making the Scots the butt of jokes.
There are other examples in advertising that capitalized on supposed Scottish frugality. The Studebaker Scotsman automobile, for example, was so named because it was a low-priced model (read more HERE). And Scotch tape got its name -- and its distinctive plaid packaging -- from the same stereotype (read more HERE).