I think it's a fuzzy line, and not one most people can distinguish, since they don't know the real motivations.
For example, if I dressed however I wanted to, I would generally dress in neo-Victorian. Mostly black, but also some ivory, red, etc. Not because I want to stand out, but because I genuinely love Victorian clothing and I think we look like slobs today by comparison. There are also all kinds of sensory reasons Victorian clothing feels good- for example, corsets are supportive and ensure good posture, and I find them really comfy so long as they aren't done up too tight, and it's a great feeling at the end of a day when you get out of one.
Most of the time, I tone down how I
would dress because it is
too different. I do this in order to blend in for a variety of reasons- for work, certainly, but also because I don't want people to find me so odd on a regular basis that they don't communicate with me. So in a way, I'm toning down "the real me" to a version that allows for more communication. More attention, in a way. Or maybe different attention.
Now, to people who don't know me, they may think when I do have an occasional night out and really go all-out with my clothing to what *I* like best, that I am doing it for the attention. Well, I suppose in some small way I am, because I very much like the attention I get from my husband.

And the compliments I get on the outfits I put together are nice, too. But mostly, it's just that I'm finally succumbing to a night of being
me. Me without worrying about what is office-appropriate, what will blend in enough, what won't offend anyone, and what will challenge stereotypes without reinforcing them. I'm just looking in the mirror going, "I really like black fancy stuff. That feels me-ish."
It's an insider vs. outsider perspective. No doubt, if someone sees me with the black hair, tattoo, Victorian clothing, and whatnot, they think it's for the attention. But if I do get attention, which I'm fine with, it is just a secondary benefit as I see it. It might feel good, but it's not why I'm doing it. There have been plenty of times I've dressed up to stay at home, or just to go to friends who could care less and have seen me like this dozens of times anyway. In my case, it was a long slog to get to where I was unconcerned enough about negative attention that I finally started making my body express what I felt was "the real me."
Of course, for this reason, I also don't try to "be goth." If I'm in the rare mood for khakis and a green sweater, I'm wearing it. When I go to the barn, you can bet I wear sensible clothing. I forego white makeup because it's not a look I enjoy and it clogs pores anyway.

Still, if you saw me on the street, would you know any of these things? Nope. Which is one of the reasons I tone it down. I'm aware of people's categories and I'd like to represent myself as honestly as I can- in the gray area between them- even if this means simultaneously not being exactly who I feel I am. Not sure if that last sentence makes sense... but hopefully you get the idea. Sometimes to express who you are ideologically, you have to do something a bit different from expressing who you are aesthetically.