"Things You Wouldn't Know If We Didn't Blog Intermittently."
Assuming all people in Africa look alike... ignoring distances and history and migration and instead adhering to the concept of 'race' which isn't 'Race' isn't a scientific concept to begin with... it's putting people into boxes according to some visual traits and not others. Ignorant of the underlying complexities and looking only at the extremes of the continuum.
It even goes further....A white person from South Africa is also an African.There is indeed a form of gatekeeping going on, as if people who have never even been to Africa, and are perhaps five or more generations removed from Africa, are now the ones who "know" real Africans, etc.It's almost a kind of purity test.
You may also want to look into "colorism."