These images use darker, somewhat depressing colors, and shapes that seem impersonal, even intimidating. I like the overall gloomy feel it presents.
To the amateur psychologists out there, this has nothing to do with my personal mood. There are plenty of things in the real world to make me happy, sad, hopeful, angry, disgusted. My personal mood may affect my energy, my desire, to create art, but it does not inform the art that I create.
Think of this image as a fiction. I enjoy these darker pieces in a way similar to a novelist delights in creating a dark and wicked villain.