Exactly right. Gender is performance. We commonly enhance this performance through clothing, the way we speak and how we refer to ourselves; this is not the only ways with which it's done though. I think it would be rude to criticise a trans man for affirming their gender by growing a beard for example. However when it comes to cis men in particular, the way they reinforce their gender is often mocked. So what if the plants some grows makes them feel more comfortable in their gender.