Usually I get reports that say something along the lines of "that's nsfw" (which isn't very convincing) but your post changed my mind because it gave me an insight into how other people may perceive this pic:

The point of tagging something as NSFW is not that it could be full-blown hardcore furry anal porn, it’s that something may be construed as porn. Regardless of what you and I consider NSFW, mildly risqué could be considered as porn in other situations by other people.

I still personally disagree with with flagging a pic depicting a person wearing a lacy bra but I don't want to get anyone in trouble and jeopardize their job, especially in this economy.