24 of the 45 pieces here - that's 53% - the majority!...
...have something in common...
#'s
46, 47, 48, 49, 51, 53, 55, 57, 60, 62, 65, 67, 68, 69, 70, 71, 73, 77, 78, 80, 85, 86, 89, and 90...
Now, I ask again:
...Was there a meeting, a conclave, a gathering, a symposium - where all these artists agreed to use the same symbols? How do these same symbols appear over, and over, and over again? Despite being separated by years and continents, time and geography, time and space? HOW???
(It's just wonderful!)
The answer is so Rudolf-the-Red-Nosed-Reindeer-blindingly-obvious that even you should get it: The artists all painted with The Little Drummer Boy playing in the background:
But a lamb is too small, so....