This is a beautiful cloud - the light is perfect. Excellent exposure and focus. I also think you did well with the composition; by putting the brightest area off center and giving more space to the darker area, you balance the piece nicely. If I was actually there, I know I would be drawn in and could spend a long time watching it change shape and color and admiring its beauty. That said, a picture of a cloud with nothing else in the frame rarely holds my interest.