Horn Of Plenty
November's window is a cornucopia. Legend has it that the first cornucopia was a goat horn given magical powers by Zeus and that the keeper of the horn was granted whatever they wished. My cornuopia also has magical powers...well, power. From the back side of the painting (seen below) you can see that the apple was left unpainted.
Thus making it an enchanted apple serving as a porthole to the great lobby beyond!
So maybe it's not as good as a wish granting horn-of-plenty but it's the best I could do.