I was drawn to this picture, and the cleverness of putting what would normally be the subject of the typical photograph, as the out of focus background. Very nice! I do agree with Thilo that the DOF is maybe just a little too extreme, but I really love this shot.
I like your idea of showing notre dame with a focussed flower. I would suggest to open the aperture a bit as to my personal opinion, the DOF is too strong here.