The similarity to Double Spearhead Tessellation is most apparent in the back-lit picture. The two are compatible in that they can be combined in a single model. Their Crease Patterns (CP) also share a lot of similarity: the creases are all in the same places and only differ in their mountain-valley orientation.
The grid in this fold is 18×18. Paper (probably Thai Unryu) courtesy of Satoko Saito.