Just got mine. Goes along with the "valentine" theory others have suggested. Also, to those unaware, the QR code leads to hubski.com
As much as I get the fun behind Sherlock Holmes-ing all the letters into uncovering a secret plot, I'm more than happy to just wait for the letters in Valentine to unravel one by one in cool individual designs. Why make a mystery out of it, just enjoy it all coming in, and this place coming together. _refugee_ you're like the love Santa Claus.
There are one or two secret "easter eggs" sort of turns to this. One won't be clear until all the letters are assembled. If lil can't take a picture of her letter it might be helpful to know what the paper it is printed on looks like. The other one is individual. Unfortunately I couldn't do it with all individuals but I tried. Just think about your letter.