He relaxes a bit further at that, signaled by a pout slipping into his expression. Writing letters. Not that he generally disapproves but the way Maglor says it it sounds really tedious...

"But we needed as much as we could, and nothing got damaged. We were really careful with everything and put only things in front of your door that were really sturdy!" It's not like it was a prank pulled off carelessly or without thought put into it!