White flat surfaces are white and not mirror like reflective because of the irregularities of the surface that that causes diffused reflection. Due to this diffused reflection the light rays that are coming to the surface gets reflected in an irregular manner and thus do not shine as they do in case of mirrors. Diffused or irregular reflection occurs when light rays coming in one direction strike any uneven surface and gets reflected in various directions. Thus, preventing the surface to shine. In case of mirrors, the surface is very smooth and the light rays incident gets reflected at an angle equal to the angle of incidence and since ALL LIGHT RAYS COME PARALLELY AT THE SAME DIRECTION OF OUR VISION< THE SURFACE SEEMS TO SHINE.

White flat surfaces are white and not mirror like reflective because of the irregularities of the surface that that causes diffused reflection. Due to this diffused reflection the light rays that are coming to the surface gets reflected in an irregular manner and thus do not shine as they do in case of mirrors. Diffused or irregular reflection occurs when light rays coming in one direction strike any uneven surface and gets reflected in various directions. Thus, preventing the surface to shine. In case of mirrors, the surface is very smooth and the light rays incident gets reflected at an angle equal to the angle of incidence and since all light rays come parallel at the same direction of our vision. The surface seems to shine.