that is not the "average" attractiveness of women from each country
it is just what you get when you take all the female faces and combine them into one
therefore the anomalies that make women less attractive are cancelled out
if you took a sample of 1000 ugly women and combined them into one face like they did here, you would also end up with an attractive female face since all the anomalies that make women unattractive get cancelled out, it doesn't mean that the average female of that group is actually attractive