Here is a more QM explanation:
When a photon interacts with an atom, three things can happen:
elastic scattering, the photon keeps its energy and changes angle
inelasstic scattering, the photon gives part of its energy to the atom and changes angle
absorption, the photon gives all its energy to the atom and electron
Now there are visible and non-visible wavelength photons, but in your case, only the visible ones are more important, so I am going to talk about those (except for absorption and re-emission in which case the absorbed non-visible light might be re-emitted partly as visible wavelength light).
In your case, the visible light we see from an object is mostly from its surface, there are two cases for visible light coming from the surface of the object:
specular reflection (mirror or shiny surface), this is elastic scattering
diffuse reflection, (not mirror, faded), this is absorption, and re-emission
Now it is very important to differentiate between specular reflection and diffuse reflection, because:
in the case of specular reflection, a mirror or a shiny metal, you will always see the mirror facing towards you lighter, then the mirror facing a little bit away from you
in the case of diffuse reflection, like a wall, you might either see the wall facing towards you lighter or darker then the wall facing a little bit away from you, this is the case you are referring to
Now you are saying that it is possible that a wall that is facing towards you is appearing darker then a wall that is facing a little bit away from you.
Yes it is possible, because walls are typically creating diffuse reflection. In the case of diffuse reflection, most of the visible wavelength photons are absorbed by the surface atoms in the lattice, and then re-emitted. Now in this case, the photons do not keep their original angle of incidence, and do not keep their relative angle nor their relative phases nor their energies. That is why in this case you do not get a mirror image, but a faded reflection.
Now the reason why the brightness of the wall facing towards you might be darker then the wall facing a little bit away from you is because even though more light should be reflected towards you from the wall facing towards you, the photons on that wall will have diffuse reflection, in which case the angle of reflection is random. It has nothing to do with the angle of incidence.
Now there is one more thing in the case of diffuse reflection. With absorption and re-emission, it happens, that even non-visible wavelength photons get absorbed by the surface and then they are re-emitted in multiple steps, in different wavelength photons, some of which will be visible light. That is why that a wall facing away from you (but towards the light) might absorb more non-visible photons by the surface, and then those photons get re-emitted in multiple steps and some of them as visible light creating an effect as if the wall was brighter.
In this case, like a wall, or a material that has a lattice structure, it is basically depending on the structure of the lattice atoms, how they reflect the photons, in random ways, but these random ways might even create certain phenomenons, where the wall facing you will appear darker.
You know, there are those materials, where from a certain angle, you can see a picture, but not from a certain other angle. Now i just saw a car painting, that was made so, that from different angles, the car's certain parts appeared in different colors, and if you moved, the car appeared to change colors. These are just examples of the same thing.
You can create certain materials, with certain surfaces, where the surface, viewed from a certain angle, will reflect light so that it will appear in a certain color, and then from another angle in a certain other color.
Now in your case these colors could be a darker color for the wall facing you, and a brighter color facing a little bit away from you.
But normally, in case of a wall, that you are talking about, yes it is possible even without these special surface materials, to have an effect, where the diffuse reflection will make the wall facing you appear darker, and the wall facing a little bit away from you brighter, just because the angle of reflection is random and has nothing to do with the angle of incidence.