Being trans is about your inner essence. Your gender identity is an internal sense or feeling. It is unrelated to your gender expression, which is how you present your gender to the world.
You can feel like a man, or a woman, or neither or both, or unending combinations of all of these, and this gender identity may be reflected in the way you dress in ways coded by your culture as masculine or feminine, or non binary. But it also may be hidden within you, and the way you appear, for various reasons, as culturally coded, doesn't reflect anything about it.
This is the justification for telling everyone not to 'assume gender', and it's also the reason why hulking great bear men can demands the right to wander into a female space without censure because the inner essence is entirely unrelated to the totally masculine body and thick facial hair and masculine coded clothes.
This particular instance could possibly be a useful starting point to discuss why a woman would reject the physical fact of her womanhood, and claim to not be one, while embracing every trapping of feminine coded presentation enforced by a patriarchal society.
It's almost like the most perfect example of rejecting the idea of slavery while cheerfully being enslaved and insisting you are much better than those slaves over there because you've chosen to be enslaved and they are still fighting against it.
The idea of fighting against gendered stereotypes by saying you don't have to be a woman to be feminine, and vice versa, and then celebrating the femininity rather than the actual diversity of being a woman.