[lotharbot]

In addition, it mimics what a right-handed person already does with their hand when pointing at something on a page or on a screen right in front of them, especially left-to-right text (using the right hand so it doesn't block the text). Pointing at something off to the side (outside the width of your shoulders) makes your hand tilt outwards; pointing at something directly in front makes your hand tilt inwards.

[dllthomas]

"(outside the width of your shoulders)"

Strictly speaking (after observing myself pointing) it's "outside your elbow", right? Which coincides roughly with "width of your shoulders" when your elbow is at your side or your elbow is straight, but can differ by up to the length of your upper arm...