Christmas card, came from a 19th Century chromolithograph of a portion of the "Life of Christ" window at Chartres Cathedral. (The best commentary on the entire Nativity of Christ in both Matthew and Luke can be found in Raymond Brown's The Birth of the Messiah.)
This image was linked to the Christmas Mystery phrase, "had just settled our brains for a long winter's nap," the eighth line of Clement Clarke Moore's famous poem, "A Visit From Saint Nicholas." The obvious linkage is that in both the phrase and the image, someone is sleeping.
The puzzle to be solved was created by dividing the image of Joseph's Dream into 36 equal rectangles. Beginning with the rectangle in the upper left, each letter of the alphabet was assigned to a rectangle, moving to the right in each row. So the images of the first row were assigned letters "a," "b," "c," "d," "e," and "f." This continues with subsequent rows until the alphabet is finished. The final ten rectangles were assigned to digits 0 thru 9.
The above image shows the rectangles that were not used in the puzzle with their assigned letters or numbers. The rectangles that were used in the puzzle do not have their corresponding letters showing, so as to aid anyone trying to reconstruct the phrase.
The rectangular images corresponding to the letters of the phrase, "had just settled our brains for a long winters nap" (leaving out the apostrophe from winter's, as well as any punctuation at the end of the line) were then placed in proper order in a grid of 64 rectangles. The blank space(s) between words were simply filled in with images from the past 12 months, all but one of which I had taken.
So, for example, the first three rectangular images in the upper left of the puzzle correspond to the letters "h," "a," and "d." The entire phrase can be constructed quite easily once this correspondence is understood between images and their letters.
A simple poetic clue was constructed that was intended to point the reader to approach the puzzle's images much like one would approach a "Wheel of Fortune" puzzle. The only difference being is you had to be your own "Vanna White" sleuth to figure it out!
Finally, the phrase "had just settled our brains for a long winter's nap," is usually rendered in today's printings of the poem as "had just settled down for a long winter's nap." However, the evidence clearly points to the former as being the original text that Moore first penned in 1822. Moore subsequently wrote the poem out in long hand a number of times, and one of the copies is held by the Huntington Library in San Marino, CA.
The origin of "A Visit from Saint Nicholas" is recounted by one of Moore's descendants in The Visit.