Oh good, she wears other things for actual working. The practicality issues were bothering me...
I can see how this would work for someone who's a well-known artist, because presumably she has to go to a lot of openings and events, and an arty, drapey style that's sort of above/not about trends works for her profession and image. So she can change out of her everyday clothes and throw on this interesting dress in whatever color and fabric, and she's good to go.
Somebody here was talking about the Simple Isn't Easy book recently, weren't they? They talked a lot about the idea of a uniform in that book, iirc, citing several fashion industry people like Grace Coddington, who only wears black and hasn't changed her hair since the 70s. I personally think that if you're a "regular person" with a regular job, the social consequences of being this odd would be noticeable. Even if you were great at your job, most companies and professions appreciate a bit of social grace and the ability to fit into situations without standing out too much, and clothes are one of the ways we do that in society. (Spend some time reading past blog posts and comments on Corporette if you don't believe me this doesn't still happen, and probably more to women than men.)
There have been several bloggers who have done the 'wear one dress, or just a few, for a year' challenge and I think it's a little overdone at this point. But then, for most of history most people did have only a few outfits - it's only with the rise of industrialization that wearing the same two dresses over and over is no longer necessary.