Wow, that picture does horrible justice to the mists! A poster in another thread did note that it's better to use it on skin that's already faring well, but I'm sure even if you're having an off day/week it won't look like that! I have a feeling she may not have applied it well, or got the wrong shade (cuz the rest of her looks darker), or something... don't give up on the mists based on that picture!
I'm also NC35, and I felt that I could use either Medium or Medium Dark. I haven't bought it yet, but Medium seemed decent on me, though I'm the only NC35-er saying that, the others seem to like Medium Dark, so it may be safer to go with that.