Ingenious use of a square, you cut it into 3 parts, for a triad that will form a vertex. Meticulous folding arrives at angles that will make the vertices meet with others, if you assemble it in the right order.
The result, made more lovely by folding hald the modules in dark and the other light Daiso brand timber-print paper (a little flimsy but after an age being careful it all came together), is a pair of cubes getting their “geometry” on – when you see it your brain goes wow.
I made a cube stand (also designed by Frances Ow) and together it is quite a thing of beauty. I am sure any woodworker would be able to actually make one of these (from bits of timber) – possible?