The character 反 means "to reverse" or "to return", while 映 means "to reflect" or "to shine". Together, 反映 is formed by combining these concepts to create a vivid metaphor: it describes an action akin to light (or an image) bouncing back off a surface to show a likeness, thereby extending to the abstract idea of one thing (like a thought, report, or artwork) mirroring, revealing, or giving back an image of another (such as reality, conditions, or popular opinion).