A Package

When I got home from work today my mom told me I had a package. I had ordered a small canvas backpack from Etsy to act as a purse while on crutches, so I was pretty confident that's what it would be. But I came out to find a box that didn't quite look canvas bag sized:

Size confusions aside, I went ahead and opened it. To my utter surprise, this is what I found:

And this note:

The package came from a company called "You Color Posters" in Eugene Oregon. I fully appreciate this kindness, but you guys, what? The sender has got to come forward before I go insane with curiosity. 

. . . Anyone?