Hi Bob, This does have a bright sunny look to it and I am sure that is what you were going for. I like the tight comp. Some of the yellows on the left look hot. I might desaturate it just a little, not sure if you can recover the yellows but maybe if you go back to the raw.
A dandy looking sunflower and good points raised by Denise, particularly about the yellows on left side. Nice to have iit in your backyard and handy for when center of flower pops as well.
The image forms an interesting pattern, I think you deliberately clipped the inner part of the flower top and bottom. I suspect this was to make the image appear to be a little less centrally positioned. I get the impression that DOF is quite limited despite the f16 maybe this flower is not so big as I suspect it is.