Originally Posted by the gael
When the asguardian guard returns from the dark elves world, telling Odin That Loki had been killed, look at him, I bet he's Loki in disguise. It Is when he replaced Odin ( they were only two in the room ) Loki has probably created the illusion of being injures by the blade, then he stayer on the ground, so Thor could took him in his arm. After another illusion of his dying body, eh replaced the guard Odin send and then replaced Odin, very simple for him
Yeah. Honestly, not sure of the confusion it is made almost painfully obvious. We see the green glimmer of an illusion on the guard in the Dark World. And then as you point out, his facial expressions in that scene with Odin make it clear.