The really confusing thing is to realize that everyone else's HB8+ is your HBI'mNotInterestedInHer.
Having a number's scale implies universality. If you ever sit down with your friends and discuss where women rank, the numbers will be different. At least, that has been my experience.
Theories of attraction don't measure attraction, they measure people's social-consensus appraisals of other peoples' looks. This could be more accurately called 'cuteness'. Women judge one another's cuteness all the time, but because they aren't actually sexually attracted (Im assuming!), they are just judging 'cuteness'. Until you actually want to have sex with the person or be physical with them, you are not attracted. They were not measuring attraction to the computer generated faces, they were measuring 'perceived cuteness' which is something different in my experience.