The guy in that video is obviously a rookie.
First, you don't wear tinted safety glasses indoors. Those are for mowing the lawn in sunshine. If you wear tinted glasses indoors, you can't see what you are doing. You should wear clear safety glasses indoors. (I'm not sure how many people actually wear safety glasses to hammer a small nail into a wall, but since there is always a chance that the nail could slip and bounce back toward your eye, wearing clear safety glasses is the prudent thing to do.)
More importantly, if you are hanging a large picture with a wire hanger, you should use two wall hangers, located approximately 33% and 66% across the picture. If you use one wall hanger in the center, like the video suggests, your picture will constantly rotate and hang crooked at every vibration. You will forever be straightening the picture. Two hangers and wire will help keep the picture hanging straight.