You don't understand how prejudice works and how we form our individual tastes.
If a white guy looks at another female of another race and says 'she's got big eyes like me, she's beautiful..'
or
I've even heard an african-american female say about an unusually buff and rugged looking asian guy, 'damn, he's fine'.
Simpletons would interpret this as nondicriminatory but it's still in play.
How could either one of those people or examples not be discriminatory or have their own prejudices? of course they do, we all do.
How could one not be prejudiced against asians for example when the crux of asian beauty is the smaller body build and what would be interpreted by westerners as more effeminate? so they reject it and favor what is closer in line with their ideals.
It's still preference. Preference is inherently prejudicial. That's okay when it comes to what we like. It's not okay to apply a double standard to other people.