This is really a striking image - I had no idea what it was until the whole picture came up - and while that adds to the mystery, I also think it's part of the reason it did not score higher. A bit more light on the subject I think would have helped to give this image more depth and make it more recognizeable. It looks like there is a 4th flower on the left (or is it a reflection?) and seeing just a little more of that would be just the right amount of extra light. Also, I think that the tilt of the shade is a little distracting.
All in all, though, this is a really interesting photo of a very ordinary (albeit a little unusual) object. I think you did a nice job of capturing it, and as I said before, the darkness does add to the mystery, and perhaps that's really what you were going for.