Lucifer smiles, it's a smile that says he's comfortable with both this topic of conversation and his general place in the universe.

"The photo? It's of the two of us, yes. But if you ever really want to dive into memories, all you have to do is ask. I'm always willing to hop into the SIRE with an inmate and go spelunking."

The SIRE is possibly the place on the ship he's most comfortable, for a number of reasons.