The answer is motif :) any reoccurring theme, pattern, idea, image etc. in a work applies to this.
for example, an artist that includes flowers in across all of their work (or a series of it) would be depicting a floral motif. I hope this helps!!
the first photo is of a natural element, hence that its nit man-made. the shape of the first photo is more geographic then the second photo.
the second photo is of a side walk, a man-made object. the shape of the second photo is of a square, a square that was man-made, had to be put in place.
1.Bachelor’s
2.Dr
3.masters
I could be wrong