How can photography produce small and fresh pictures? This color contrast is particularly lovely. Is it some kind of post-production?

Hello, yes, first of all, answer how to shoot a little freshness: you need some "props", such as writing paper, objects, background cloth or a large green leaf, plus a good camera and a large aperture lens, the effect depends on the photographer's brain and experience.

Answer the color again: as far as the picture is concerned, it was colored by photoshop and other software in the later period. If you don't know photoshop, you can try to use the light and shadow magic hand software, which has nostalgic effect and so on.