The symmetry story is true, but only works this way to a certain extend. A face thats more than 95% symmetrical is actually unattractive and scary even to most people. Then again, you won't see a 95% symmetrical face that often in real life
..
And attractiveness is about more than just symmetry. It's, besides that, also about sizes, ratios and distances all over the face and body. But I don't think it was the TS's intention to go there..