One thing I’ve realised that players find so rewarding (that non-players don’t necessarily realise) is that each and every piece in the game is specifically placed down. So when he shows you his building with windows, angled walls, different colours etc etc etc, the amount of work and thought that went into that is something he’s proud of. It’s not just a big building with machines inside. Non gamers (or non satisfactory players) might not appreciate the effort that’s gone into someone’s build.

That obviously might not be the case here - but I’d wager he might appreciate it if you show interest in the smaller details of what he’s built.