With it in your lap, flat, your head tilts down, bending the neck. This puts strain on the muscles at the base of the neck, which tires them. The muscles under

With it in your lap, flat, your head tilts down, bending the neck. This puts strain on the muscles at the base of the neck, which tires them. The muscles under the shoulder blades will then step in to try and compensate, tiring them, etc., etc. This is why it's uncomfortable to to read, sitting up, with a book lying flat on your lap. With a laptop the screen juts up at an angle from the lap (~45 degrees) which allows you to look at the screen longer without becoming tired (less neck strain). Of course if you're just half propped up on the couch this might not be the case. Admittedly it's probably harder to accidentally knock this off your lap while reaching for your coffee/beer/whatever. I could see it on the wall, but if it's for mounting, why worry about making it light? You can save on material costs by going heavier.