As far as I can tell, they physically present as masculine (albeit non-traditionally), perhaps with elements of femininity (I mean when it comes to specifics that kinda stuff is subjective), rather than butch/masculine femininity or smthn.

I just checked their reddit acc (u/anarcho-stripperism) and they still have their preferred pronouns as they/she/them, and seeing that they're anarchist, perhaps they are going for a more subversive breaking-the-gender-binary thing (which I think is cool!) rather than something specifically about gender identity.