Nice job with capturing the butterfly! Now that I think of it, I don’t think I’ve ever done so myself!
Personally, I think both photos could be much more dynamic if they were composed on a third rather than the centered composition. The photo with the butterfly seems unevenly weighted (there’s a lot going on to the left of the butterfly, and mostly blank space to the right), and the photo with the sunflower is fine, but it’s just not drawing me in. I’m not finding myself wanting to gaze at it and explore every detail of the photo.
I do like how the petals of the sunflower are so crisp and clear!