One of the most common patterns is what I call the “butterfly”, but JJ thinks it’s a flower. Take your pick.
When you build a stone screen with blocks that are the same forwards backwards and upside down, there’s really only one design you can end up with.
If you focus your eye on the center of any given block, you get the butterfly/flower.
However, there’s really 2 other different patterns that shows up if you look different spots in the over all design.
This pattern becomes dominant if you focus on the top and bottom edges of 2 adjacent blocks.
And this pattern shows up if you focus on the side by side edge of two adjacent blocks.
3 for the price of one. Try it yourself on the top photo.