Double exposure, a photographic technique, is used to create dreamy, surreal, additional or alternative layers to scenes in a photograph. This style often involves adding other images to blend with the original one to create a unique effect. In this case, the photorealistic concept uses light particles, glowing points, prismatic reflections, and other striking elements to create a mesmerizing masterpiece.

In the second part of the description, it talks about kids wearing superhero, astronaut, and pilot costumes, engaging in play, laughter, and dreaming. The scene seems to capture the imagination and innocence of childhood, completing the atmosphere of the first.

In summary, this double exposure technique is used in photography to create fantastical, dreamy elements within reality-based scenes using light or unique textures, such as those represented by particles and glowing elements in the provided description.