First, let me say that I do a lot of flower shots. I know what goes into them and I know the thinking behind them. That said, if I were voting on this in a basic challenge, I would give it a 7 (6 in advanced). White flowers are extremely difficult as they essentially come with blown highlights. :) Because of that, you really have to watch your lighting and not over-light the scene. I like the overall texture here but I would like to see a little more texture in each individual petal. I am not a fan of that shade of purple. Personal preference. Also, having the background match takes a little away touch of purple in the center. But, I could think that just because I don't like that color. The composition is good. I am back and forth on the depth of field used. I like what you have and at the same time I like to see it deeper. Overall, a good photo. Just needs a little oomph from lightly more dramatic (less bright) lighting. To score an 8, fix the background color - black or white works for me. :) To score a 9, give me more raking light or back light - somethign with a little more drama. I think Tuckersmom and Sher9204 have some of the more beautiful images of flowers that transcend the genre.
I gave this photo a 1 because it didn't seem to me to fulfill my expectation of a "still life," a classic form of artfully arranged objects. Call me narrow minded but that's the way I see it. That being said, it is a very pleasing image.