I was reading a discussion somewhere online (probably the Usenet newsgroup rec.arts.sf.written) of a story I had not read, and someone referred to "the woman on the wall" in the story. I misread it as "the woman in the wall" at first, and various macabre images came to mind, but then I realized it was "on," and my first thought was that this was about a flat image of a woman that was on a wall, but somehow alive.
Not long after I was invited to contribute a story to the anthology Graven Images, and decided it would be the perfect market for my woman-in-the-wall story.
So I wrote it, and they bought it. I thought it was a pretty good story. Alas, the anthology did not get a huge amount of attention, and therefore neither did "Heart of Stone."
Then a decade or so later ebooks caught on, and I tried a few experiments, including turning old short stories into 99-cent ebooks. "Heart of Stone" was one of them, so if you have a Kindle, you can read it. I cobbled together the cover (there on the right) out of a public-domain photo of a wall, and a Botticelli painting, and there you are.
And no, I don't know what story the original discussion was about. If I ever knew, I've long since forgotten.
That's it; here's your list of handy exits: