Media's part of it too. You see the girls in movies and cartoons that are supposed to be beautiful and they're usually fair with delicate features. When every time someone who is supposed to be 'pretty' looks completely different from you, and you don't see anyone in media who's 'pretty' and who also looks like you... well then nobody needs to TELL you that you're ugly. You internalise it.
There was
this viral video of this little girl. She's so little that she shouldn't have had these thoughts already. But children are observant. Black women celebs responded to it and everything but the thing is... you can tell someone they're pretty but if the whole rest of the world is hinting that they aren't pretty, they won't believe you. Or they won't feel pretty. The world doesn't need to tell you you're ugly, all the world needs to do is point out that those who are pretty are those who don't look like you.