I'm finding it difficult to determine in which area of the photo the focus lies. It might be that the shapes would be easier to make out if this was zoomed out a bit.
On camera flash? That's what it looks like judging from the shadows. The best light for shooting flowers straight on is probably overcast. Straight on with flash causes more shadows. Flash fill can be beneficial if shooting more from the side on a bright day to soften the shadows of direct sunlight. Hope this helps. :)
I have a very similar submission where the 'heart' of the flower is orange. Sadly I am being rated poorly based on the fact that the entire flower isn't orange. I hope it's going better for you. As far as your composition, I think the croping takes away a lot of the context. The center doesn't really stand out on it's own and cropping in the entire flower may have given it more presence. Maybe you chose this crop to emphasize the orange.