Reading between the timel[lines]? Through choice? ALICE AI used to control?
Reminds me of a saying,
A story we wrote that we have forgotten we wrote.
Now, why write it to begin with…? To remember? To share?
I think the purpose of "looking back" is to observe from a different (future) perspective how decisions and happenings could have been different if different choices/happenings were made at that point. And to learn from this ability of "looking back" in order to see clearer. Quantum mechanics in basic form. I.e. in another timeline Trump wins the election, yet we did not observe this, most likely to learn from it. The end is always the same, but free will dictates how and when we get there. Read between the Time[lines].
I think it's more like, what did we need to Learn by observing this timeline.