I'm wondering if this is just poor piecing?
I'm noticing all the lopped off points on the 'star'; and look at the straight edges of the diamond shapes pieced next to the curved elliptical shapes....it would have to be 'gathered' in order to fit together. And that would make a bunched center which appears to be covered by a circle to hide the effect.
Interesting. And not unpleasant at all when finished, washed and loved!
Jan in VA