What is this scene about? Random artifacts of time travel. Why does it matter? It doesn't. Not really.
Anne walks into Mag's room [who? what? when? never you mind, not important.] to find that Jacob is again singing to her. As is usual for him, he's sitting on the floor with his back propped up against the bed. As is usual for her, Mag is unconscious.
Anne waits until Jacob is finished to speak. When she does she says, "I don't recognize that one."
"You wouldn't," Jacob says; "it hasn't been written yet." Jacob gives a mirthless laugh. "It's younger than I am."
Anne doesn't have a response.
"If we can't restore the primary timeline then your granddaughter's flac player," Jacob notices Anne isn't familiar with the term, "her music player may prove to be the most valuable artifact in all of history.
"We can all pine for the lost works of history, but what could compare to records from a future that once was but now never will be?"
"You're worried you won't make it back," Anne says.
Jacob shrugs, "Be stuck with you people for the next twenty five to life? Of course I'm worried, but I worry about a lot of things. Don't worry about it."
The conversation moves away from lost futures when Anne asks, "Has anything happened that I should know about as her doctor?" of Mag.