Thanks Mike, this is a more appropriate spot.
Let me rephrase (Mike, please hack off my original post if you like to avoid confusion, thanks!).
I realize the effects of lighting play a significant part in the "mood" of a painting or drawing. And the choice of lighting is also highly subjective. Different people react differently. For example, some may like the silhouette look of the image you posted above and some may say "use a spot meter!"
I assume the choice of lighting is a deliberate one for most painters and drawers. Then I am curious about what criteria justify what choices and for whom.
For example you judged "A pair to draw to" image as appropriate for a portrait. In terms of the mood such lighting produces, why is it so? Hypothetically speaking, if you could have all weather conditions and lighting arrangements in the world, what would you rather have your subjects be lit under? And what justifies that choice? Keep in mind though the scenario needs to be one that has already been tried out and deemed satisfactory. Something like "I PREFER TO POSITION MY SITTER UNDER THE DUST CLOUDS ON MARS " is not quite the answer
Thanks!