where should you aim? I wondered after watching this.

You're intended target.

So my mind was on the right track. Thank you.

Hold high, magazine side, to accommodate which way you might have the rifle orientated. Now granted I've only done sideways with M4's, but high side magazine side works for me out to 100, beyond that I run out of skill.

Some people when shooting out of a hole that's low approach it either by bending over, both knees on the ground, with rifle in its normal shouldered position, rotating the rifle sideways magazine towards torso, and I've seen people prone out and get as low as possible and the magazine away from torso, hence knowing where the magazine is orientated will dictate aiming point.

Hope that both makes sense and helps.