Masterpiece illustration featuring a low shot closeup of a child sitting on sand with a bright smile and adorable expression. The child has exceptionally detailed big eyes and blonde hair styled in pigtails. They are happily engaged in building a sandcastle using a plastic bucket, surrounded by shells and sea life. The scene is illuminated by dramatic sunlight with lens flare effects, set against a beautiful beach landscape. The image is rendered in stunning detail at 16k UHD HDR resolution. Small whimsical elements like a gentle breeze tousling the child's hair and seagulls flying in the background add charm to this vibrant and joyful beach moment.