"Beauty queens" is a terrible group to sample from. It is not in any way whatsoever random, which is what you would need to study. "Beauty" has many subjective components, which can change rapidly.
But that's not the point. Take 20 girls from each country who are considered by some popular standard to be beautiful, and measure variation. Since I'm assuming plastic surgery is not that widespread in DPRK, the results would be interesting, even if not very useful.
No, we just measure variation according to some algorithm. The beauty is subjective based on standards, and the results would definitely be biased by that subjectivity.