Am I bisexual or a full-blown lesbian?

I have always said that I am bisexual, but lately I've been seriously wondering whether I'm a lesbian. I do find guys attractive, but it's like a whole picture attractiveness, rather than small details. To clarify: sometimes I'll look at a guy, and instead of scanning his whole face, in a quick glimpse I will be like, "Yeah, he's hot." With girls though, I go over all the details - the way her nose crinkles when she smiles, the different variations in her eye colors, the shape of her jaw, etc, etc. I somewhat take pleasure in the small details of a woman's face, but with guys I don't really care about all that stuff. I am also more mentally and emotionally attracted to females. So what do you think?