Sorry this one's a little late.
Trans people have to walk this really fine line with respect to acceptable gender expression. Deviating from what is considered 'normal' for their gender results in the credibility of that gender being called into question in ways that just don't happen with cis people.
(while this happens with all trans people, I'm going to focus on trans women for this post)
The truth is, while feminism is making awesome inroads in creating space for women to adopt a range of gender expressions beyond what social norms of 'women' have prescribed, so often that only applies to cis women. Trans women who 'break' femininity are regarded as essentially 'letting slip' their 'actual gender'.
This is a symptom of the fact that trans people are largely still considered to be 'acting like ' their gender - 'acting' being the operative term. People see their gender as being something that sits upon a deeper truth - some less genuine, something deceptive.
There's another side to this, of course, for trans women who adopt non-transgressive expressions of femininity - they're accused (often within the feminist community) of reinforcing stereotypes, damaging the image of women.
So there's really no way to win. Trans women who conform too much are essentially accused of being in bad drag, trans women who don't conform enough are accused of a lack of commitment to their gender.
That great work we do, where we're troubling what gender norms are, challenging sexist ideals, and taking control of our bodies? We need to make sure that we're opening up those opportunities for ALL women. And we need to make that space available for all other genders, as well. I don't believe in feminism that opens doors to some people while locking them for others.