I think it comes down to being comfortable in your chosen clothing. Not necessarily physically comfortable, but just that restful feeling when you get dressed, "Yes, this is good for me." And then usually forgetting about it, since you're so sure in what you're wearing.
Taking your example, it sounds like that politician is dressing for what's culturally typical of her role and title, but is not herself comfortable in that clothing. Similar to how you can tell women who are not used to wearing heels (high or not) - they move more tentatively and walk like they're having to think about it, not as naturally and thoughtlessly.
Joy's example... now, that lady may be truly comfortable in what she is wearing. Or she really may be making a statement. Or she may be identifying with an alternative clothing/life style, like goth, lolita, rockabilly, punk, vintage, hipster, etc. Ironically, it may *not* be the real her, but the identifying. It takes a lot of time to assemble the pieces for an alternative wardrobe, and it may remain a habit even as one's preferences start to change. I did the same with vintage for a while.