There was a time when it was popular in England to have elaborately dressed African servants, often children, simply stand behind you when you sat for a meal at a social function. I believe this was during the 16th and 17th centuries. The darker their skin was, the more it was a status symbol for their white employers (or owners).
That’s what the brooch reminds me of. Like the controversy over “black Pieter” in the Netherlands, it shouldn’t be sugarcoated.