Does the sun shine on the river like gold?

That's right. When the sun shines on the river surface, the light will be reflected from the water surface back into the air, forming reflected light. Light will also refract in water and spread upward from the bottom of the water to form refracted light. These reflected and refracted rays are interwoven on the river surface, forming an effect that shines like gold. This description is often used in literature and poetry to describe the beautiful effect of sunlight on the water.