Playing with painting

Why do I find myself every now and then in a state of mind, where I have to look at a painting through the viewfinder? Am I stealing somebody’s mood or inspiration? Occasionally, I feel that I have to use an artwork in a more brutal manner for overlay or superposition a piece of it with something or somebody. And if it were not enough, things go worse: from time to time I dare to play in paintings as if I were an artist. I have no idea why this happens, what I’m looking for and how to find it…