This shot certainly meets the challenge. I think the lighting is a little too harsh, and I would enjoy the shot more if there were little or no shadows. I think that moving in really close to the primary subject so it fills the frame would help improve the overall impact. The background is a little distracting, which could be fixed with a more shallow DOF. Good strong colors.
YOu found a great specimen of sunflower. Unfortunately, the background is a bit busy for the blossom. Maybe a little less depth of field. Then, that white stick, well, needs to be someplace else...
;>)
Still, a nice effort.