Well, it's all you've got, ultimately. You can't categorize people just on their word, and you can't categorize them based on any of the biological criteria since you don't know what their chromosomes or hormones or genitalia are when you see them.
And it's not purely about clothes. Even if you look at people adopting more clothing styles traditionally associated with their other gender, say Harry Styles at awards shows, they do not style themselves exactly as the other gender would. Ultimately gender is a social construct, and that involves some shared performance that we each choose to adopt when defining ourselves in relationship to everyone else.
And it's not purely about clothes. Even if you look at people adopting more clothing styles traditionally associated with their other gender, say Harry Styles at awards shows, they do not style themselves exactly as the other gender would. Ultimately gender is a social construct, and that involves some shared performance that we each choose to adopt when defining ourselves in relationship to everyone else.