I believe that beauty is one of those things that cannot be easily defined. There are just far too many factors to be considered. The fact that this is likely only "true" Germans, judging by the lack of other races being used in the study, automatically seems to make the standard more narrow. So this could hardly be used as a cover-all.
Also, since people have flaws and different particular things that makes their own face unique, there are things that help and things that detract, which makes a universal definition of beauty impossible to gauge.
For example, there's "beauty moles" put one in the wrong place and see how that looks?
Plus, in the end, people have different tastes, so the old cliche, "beauty is in the eye of the beholder" still has value.
And my take on the mixed=pretty thing, is that harder to obtain seems to be valued higher. So, in a universalized world, if you want some Asians, go to Asia if you want some Africans, go to Africa. Plus, in metropolitan areas, they're coming to these areas so the "rarity" diminishes. Plus, take into account that there are also dominant genes to account for, so a mixed person might not necessarily look mixed in the first place. Therefore, it takes a certain mix and you can't necessarily, just run to one particular place and find them...
Voila! You have yet another idea of beauty.
But these ideals are so fickle. Take a look at the past. Bigger was better, since the poor had no food. Lighter was better, since the darker skin meant that they were common workers in who were in the sun all day.
Nowadays, it's not necessarily stressed to be light or dark. Plus, being born a certain way loses its value with all these surgeries and products. Want to be darker even though you're stuck inside working most of your life? Tanning beds! Want straight hair? Relaxer! Want to be a blonde? Bleach!
The list goes on. But as it is much easier to put on weight than to lose it in America with all this fast food and ridiculous portion sizing, then thinner becomes ideal.
The harder, the better, the more beautiful. That's just how things seem to work. Who's clamoring to be the "commoner" after all?
Anywho, that's my two cents.
i kept looking at her in that movie, and was thinking, that she's not super sexy or super groomed, but she's striking & vulnerable...and specially when they showed her next to that "American starlett", who looked so plastic & fake. 
Oh and I'm American - I have never been to a 'fast food' restaurant in my life. I wouldn't dream of doing it either. Those places smell really horrible. 
