I can't speak for the GP commenter, but from my own experience being non-binary, I have to expend cognitive energy every morning thinking about what I'll be doing that day (what meetings, any errands, etc), before deciding what clothes I can wear. If I'm staying home all day, with no meetings, or only meeting with trusted colleagues, I will dress differently than a day where I need to go to a store, or if I need to meet with coworkers I've never met before.

For trans people, just existing without conflict or judgement from others is a constant struggle between society's normative expectations and the desire to express who you really are.