When a four year old wears a dress and plays with dolls, are they doing it for a sexual practice? I don't think so.

Your response seems to imply that if a cis woman puts on a dress and walks down the street to buy a cup of coffee, then it is not sexual, but if a transwoman does exactly the same thing in exactly the same way, then it becomes sexual. Why?

Let me pose a possible explanation: Perhaps the difference between these two scenarios is in your mind, not the cis or trans woman's. In which case, the trans woman cannot really do anything about the sexual thoughts in your head, can she?

"What else does gender actually mean, if it means anything at all?"

This is just restating the question I asked. But: I have a gender, and it's my gender when I'm eating lunch, and when I'm brushing my teeth, and at all times in between, and those are not sexual practices. I put on clothes in the morning, and they are gendered clothes, but they are not revealing or sexual, nor is wearing clothes a sexual practice. So how is it different for a trans person? The greatest aspiration of most, if not all, trans people is to "pass", meaning that they become invisible and nobody know they are trans. In what way is that sexual?