In this design strokes are formed from a series of rectangles, creating thick marker lines when straight but splaying out as they curve. The strokes vary in width much more than in recent designs, so the results are much less predictable (and with the re-intoduction of a larger range of hues, often ugly). The lack of rounded corners give the design a glitchy aesthetic which work well.
I picked quite a tame result to turn into the jigsaw - not too far from the gradient effect seen in 019 - but I enjoyed following the edges of the larger block-coloured shapes to complete the composition.