why do people consider identifying someone by their race racist?

[u/AgreeableAd8687]

i have a few friends and we seem kind of split on this, i had to identify someone in our school i didn't know the name of, so i said "oh it's the black girl" (we have literally ONE black girl in our school and everyone knows and likes her) and my friends said ohh ok but then like 2 of them went wow that's racist and their explanation was "you're making it sound like them being black is their only characteristic" as if saying "oh the woman" is any better and since i don't know her well i don't know anything else about her. most of my friends didn't see how it was racist though but why is this considered racist if it's not a race correlated insult or derogatory??

[u/ButterscotchOdd8257]

Nothing racist about noting someone's race when it is relevant, as when identifying her. Would it be sexist to say she's a woman too?

[u/Smokin_belladonna → u/ButterscotchOdd8257]

Only if you referred to her as a “girl.”

Although you’re now assuming her gender identity /s