On the first day of Xmas

Just a few days past Halloween, here's the first Christmas tree — incredibly tarted up, but almost invisible behind the reflections in the shop window. The reflections reveal a street in the Pearl on a sunny day. The tree can hardly bear the weight of all the sparkle, tinsel, and gewgaws heaped upon it. (Zoom to admire, if that's your thing.) 

Whatever became of the tradition of decorating the tree on Christmas Eve?