Light is controlled by optics through absorption, reflection, diffusion, diffraction, refraction, polarization, and interference. These are often used in combinations.
When light reflects “specularly”, as occurs with polished objects, the angle of the incoming incident light is equal to the reflected light. Specular surfaces are not always the best for reflecting light. Instead, a matte white paint reflects light much more efficiently than polished stainless steel, diffused reflections caused by matte materials reflects light in all directions and works much better for wide distribution of light than specular reflection. In addition, spread reflections may occur with slight irregularity in a surface, such as etching, hammering, or corrugating.
The greater the surface area exposed to light, the more light will be absorbed, in a room, the smallest wall will have the highest effective reflectance.