I'm not going to say anything specific about this prank, as I don't want to ruin it. I'll just assure you that it's Nintendo related. Now watch and enjoy!
Cool that she was able to laugh after that. The way her voice was trembling at the start was... uh. I... don't think I would have liked that prank.
I don't know how I would react, but she seemed to take it very well as she was able to laugh the very moment she realized it was a prank. And then of course the intense happiness after getting the real letter