Photo: Steve Gullick When Mark William Lewis thinks about his songs, they summon a particular image in his mind. It’s a somber aesthetic — moody and grayscale, a world slightly warped and drained of color. Consider, for example, the photograph that graces the cover of his forthcoming album, Mark William Lewis . As soon as he saw the image — shot last spring by veteran rock photographer Steve Gullick — “I knew that felt like the world I was trying to describe in my mind’s eye,” Lewis says. “It’s