This is really something that just came up in my mind, but I thought I'd share it here, even though it's likely been asked before.
How I think that atium functions is that it lets a person see someone else's relative spiritual aspect, or something along those line, as I don't have proper terminology to explain it how I wish.
Anyway, as we know, Szeth died near the end of Words of Radiance, but was subsequently resurrected by Nin-son-God. However, his soul didn't reattach properly, and so lagged behind his body when he moved, especially quickly.
This raises the question; would the atium shadow track his physical body, or his soul which is lagging? And if it tracked his soul, would that mean that he'd be largely able to cancel out the effects of atium foresight?