Fresnel Term in reflection
Reflective surfaces become more and more reflective as the angle of view approaches a grazing angle. Even a partially reflective surface theoretically becomes 100% reflective when the angle of view is parallel to the surface. This is called the Fresnel term. Reflections, either soft or sharp now include the Fresnel term in the rendering equation.
The floor has a reflectivity of 30%, but as the angle of view approaches a grazing angle, reflectivity
approaches 100%.
In the last image, the block reflection on the floor is almost as clear and
bright as the block itself, and the floor also reflects the wall behind
the block more.
The Fresnel term gradually affects the reflectivity of the surface as the angle of view changes. But it really starts to be noticeable at less than 10° from the surface.