This signed print of the moon as seen through the pine branches is from A Year in Japan by Kate T. Williamson (who also designs the socks) and is printed on archival paper. It features a tenth-century poem (which is the inspiration for the name THIS NIGHT) by Minamoto Nobuakira (as translated in the footnotes of Murasaki Shikibu's Tale of Genji by Edward Seidensticker):

If only I could show them to someone who knows

This moon, these flowers, this night that should not be wasted.

There are two sizes available: 8½" x 11" (this is the paper size, image is 6¾" x 10") or 13" x 19" (image is 11" x 16.33", fits an 11" x 14" mat opening with minimal cropping).