I disagree. The two girls have different hair and features.
I was not saying that it was the same woman transposed into different color. That was made obvious by the artist in the gowns alone! What I WAS REMARKING ON was his showing the pearls against the different skin color and then the identical 'face paintings' as contrasting to that skin.
Looking at this again, I wonder if this unknown artist was also pointing out that skin color was no reason for slavery. England had black slavery since Elizabeth I (1533-1603) but only by the wealthy and as 'body servants'. It was in the American Colonies where it was rampant. The British, French & Dutch sugar plantations of a century on, CONSUMED SLAVES in unbelievable working conditions. Still, as a portrait of two women, the artist is depicting them as identical except for skin!