This is just photonic crystals, literally the entire point of photonic crystals is to create as many interfaces as possible to give light a second/third/fourth/

This is just photonic crystals, literally the entire point of photonic crystals is to create as many interfaces as possible to give light a second/third/fourth/… chance of getting reflected. Basically why your sunglasses are shiny. The main news is using a precursor chemical and photolithography to cure hollow glass trusses, so that the interface is glass-against-vacuum instead of glass-against-less-contrasting-material.