Basil wrote:
From my 6D manual: "When you use the self-timer, bulb, or Remote Switch and do not look through the viewfinder, stray light entering the viewfinder can cause the image to look dark. To prevent the, use the eyepiece cover (p.27) attached to the camera strap. During Live View shooting and movie shooting, attaching the eyepiece cover is unnecessary."
You are taking this too seriously, I recommend binge watching a collection of classic cartoons from Walter Lantz, Warner Bros and Disney. See if you can find a collection of Rube Goldberg drawings.