The detail in this photo is what caught my eye, how the butterfly and the flower are in perfect focus and the background is blurry but as the viewer you know enough to assume that there is another flower and greenery surrounding the butterfly.  Color has a big impact in the photo as well.  Even though the colors of the butterfly do not exactly match the colors of the flower they are close enough that they are excellent compliments to one another!  The eye's focus remains on the butterfly and moves to the flower and is only distracted from the focal point of the photograph is the blob of color in the background which is probably another flower.