Nobody asked for anything. Not the airline not the immigration officer. They only asked how long I was going to stay so they can stamp either 30 or 60 days visa. I said 60 days, got it sorted within a minute with fingerprints & photo.
I am planning to extend for another 30 days after the initial 60 days pass. Can I book a bus ticket to Laos to show them? Or must it be a flight ticket? 🙂 (Bus ticket is cheaper and easier to pass on than flight ticket)