Good light, fresh butterflies, a clear shot not masked by vegetation, a good composition so the whole is aesthetically pleasing. Does the viewer prefer to see context and habitat, or a close-up that shows detail? A field-guide study or a more interesting angle perhaps?
Today, 16th August, I hear that Brown Hairstreak show best from mid-day when the sun is up. There's so much to learn and I enjoy this gradually accretion of butterfly lore.