I designed this shape over 4 years ago using a pattern from the arrowhead curve.
The Sierpiński arrowhead curve draws an equilateral triangle with triangular holes at equal intervals. The terminating point of the Sierpiński arrowhead curve is always the same provided you recur an even number of times and you halve the length of the line at each recursion. If you recur to an odd depth (order is odd) then you end up turned 60 degrees, at a different point in the triangle.
After playing around with many shapes and test pieces I finalised this design as I realised it tessellated and I loved that. Originally I wanted this drawing to be an all over tiled piece as I wanted to show 3 pieces tessellating, but I was too lazy and felt that 3 alone were strong enough.