That aside, your example illustrates the mistake in Rhea's (and now your) reasoning very well: notice that he used a behavior - roaring - as a means to ascertain whether a person was a boy or a girl, but his assessment was erroneous, and it would be a mistake to think on the basis of examples like that that the term 'boy' refers to children who roar, or is about whether a child roars. Rather, some people use roaring behavior as an indirect means of ascertaining whether a child is a boy, though they are willing to modify their assessment on the basis of more evidence.
No here is where your conclusion is flawed. They used how a person presented to be perfectly, completely comfortable in deciding on a pronoun.
And now you’re trying to fight that and claim he wasn’t comfortable with it.
But he was.
And he had all the information that you have when deciding whether you are comfortable calling a person she or he in real life.
And yet here is a whole thread of people losing their shit over a voluntary field on an anonymous message board to let people know what gender they wish to be called. And the shit-losers are trying to say, “no! I won’t! I can’t! Woe!”
By the way, as one can tell from Metaphor's posts, he is aware of the fact that humans generally can nearly always correctly ascertain the sex of a person without ever looking at the genitals. There is no point in arguing otherwise. What he is saying is that pronouns traditionally refer to sex, not to gender.
And that is just bullshit and people fail at it all the time. ALL the time.
I don’t know what rock you live under, but in addition to having it happen to me repeatedly, even when I was wearing nail polish or earring, I also *do* it all the time. I can’t tell. Happens a lot.
So your claim that people can effortlessly tell is demonstrably flawed.
I expect you make the mistake and you’re just too sure of your own flawlessness to even know it.