Now try it while sitting - rest your arm across your folded leg, or on the arm of the chair, or hold the rail/handle on the train/bus, etc. etc. I doubt you'd

Now try it while sitting - rest your arm across your folded leg, or on the arm of the chair, or hold the rail/handle on the train/bus, etc. etc. I doubt you'd want to stand to watch regular TV, so why assume you'd be standing to watch a TV on your arm?