Sappy sustained eye contact and/or saucy flirting, in Root's opinion. She's already waiting for the right moment to make the obvious joke about keeping warm together.

"The intermittent static shrieking wasn't fun," she agrees. "You're the first person I've seen. Who is 'anybody'?"

Root's potential scope of hypothetical possibilities for where she is and what's going on is vast, and there would be a strange kind of sense in it just being her and Shaw. Maybe this is a simulation. How would she differentiate her perceived reality from any other version and even know? To Root, that's not a rhetorical question; she's genuinely thinking about strategies to test it.