Brother, I do not intend to speak for gays - however, your focus on physical characteristics is wrong. My educated guess is that their attraction to each other is varied and based on no rule that I can identify. The heart wants what the heart wants - and sometimes the little head does the thinking for the big head. There doesn't seem to be a difference between straight or gay in that regard.
It should go without saying that I defer to anyone else with more knowledge in this area than I.