It is fascinating how whites look at Japanese anime and see white people and POC generally see Japanese people. It's like the black and blue dress fiasco.
I personally relate the skull shapes to different races in manga style. In anime you'll find that the majority of characters have round and flat faces. This is an Asian trait.
The codes for European characters tend to be bolder and squarer features.
This is what a white person looks like in Anime:
These are Asians in anime:
You may think that the colourful hair and big eyes are indicative to Caucasians in anime. But they actually aren't.