It's society's obsessions that wants to classify sexuality, and then make all kinds of meaningless claims like lifestyle choices, moral equivalence.
Plato's Symposium makes more sense to me: he shows many kinds of love, all valid, but he doesn't try to claim an equivalence, nor deterministic categorisation of peoples preferences. Though Alcibiades' speech, where he clearly regards it as an adolescent lad's right to be mentored by an older man, wouldn't go down well today.
What can you tell from a person's face? Evidently something, but the nature of that something is probably too controversial to be meaningfully researched.