I noticed that the face detection on K-5 frames one face with yellow square and other with white one. My observation is that the yellow square always marks the prettier person - provided they are both equally lit and not wearing glasses.
I tried several times and it always picks faces in this sequence:
1) My girlfriend
2) Other pretty blondes
3) Other young pretty girls
4) Young girls that are not so pretty
5) handsome gyus
6) me (if I'm not holding the camera, of course)
On a party during the weekend the AI-judged beauty contest created a lot of amusement and my girlfriend is no longer mad at me for buying the K-5.
Please don't take this too seriously.