What is truly puzzling about this image is that you see the doubling in the petals but *nowhere else*. That is absolutely bizarre. If your stated shutter speed is correct, there is NO way this could be caused by IS. 1/1250 is certainly fast enough to stop camera shake as well as most any kind of subject motion, and I doubt the petals on an inanimate flower could be vibrating that fast.


The center sharpness is another clue that this is not due to motion. If anything were moving--camera, lens/IS, subject--then you probably wouldn't have a pin sharp center. So I am tempted to conclude that this is an issue with the optics somehow. By eliminating what the problem could *not* be caused by, what remains, however improbable, must be the cause. (To paraphrase Sherlock Holmes.)


As to what particular optical issue could cause this phenomenon, it is quite possible it is due to a filter or some kind of internal reflection in the lens. You will have to conduct more extensive testing to confirm or refute this possibility. Best of luck.