The Earth is just providing a bit of indirect reflected light from Earth’s sunny side to what would otherwise be a starkly dark shadowed side of the moon if there was but a single light source.
Kind of like when good artists paint horses, and show a bit of light on the underbellies- this is the light that is reflected from sunlit ground or grass back up to the belly. It’s not enough to just paint the light that hits a subject from one source- an artist has to consider that light also bounces from other elements of a scene, and when it does, it often adds a hint of the color of the object it bounced off of before. If the horse is standing on green grass the reflected light will have a hint of green. If the horse is standing on exposed soil, such as iron-rich red earth, the light that bounces up onto the belly will have a bit of that oxide orange-red to it.
Yes, but I can see that, too.
So, it doesn’t really answer my question.
But thanks for the reply.