This is (somewhat awkwardly) titled "Die Madonna auf der Mondsichel im Hortus conclusus verehrt von einer Stifterfamilie" (Madonna on a Crescent in an Enclosed Garden with Donor Family). It was painted on an oakwood panel sometime in the 1450s, by an anonymous painter known as the "Master of 1456." The delightful blue, starry background was added later. I found it by looking for rosaries in all the color portraits of the Virgin Mary I could find at the Marburg Foto Archive (which is unfortunately not very well indexed).
I've had this picture on my computer "desktop" at work this month, and I like its serene quality. This has been an unusually busy Christmas season, though I expect to be back to something like normal after the Twelve Days of Christmas are done.
To wander a bit off topic -- I wish more people celebrated the Twelve Days, although I realize they are quite out of step in some ways with today's society. (Full disclosure: I'm probably somewhat biased, since my birthday happens to fall on one of the twelve. :)
In an agricultural society, I think the time before Christmas was generally quite busy with preparations for winter: gathering in the last of the harvest, cutting firewood, cooking and preserving and so forth. Correspondingly, the church's season of Advent before Christmas began as -- and to some extent, still is -- a season of preparation and fasting similar to Lent (though less intense).
Christmas Day, then, would therefore have been the beginning of all the winter's feasting, relaxing and generally celebrating. The Twelve Days of Christmas functioned more or less as a post-harvest vacation, once the preparations for winter were done.
In modern times, it seems that our (much less comprehensive) preparations begin right after Hallowe'en (in the USA at least), and the day after Thanksgiving, the celebrations begin. Before, rather than after, Christmas is now the season of parties, visits, church pageants and so forth. Radio stations play "all Christmas music" for a month beforehand.
And then suddenly on the 26th of December, it all disappears.
Well, it doesn't all disappear from my house.
Fortunately I have friends who celebrate Twelfth Night, and it's a tradition I treasure.