Thanks! Makes perfect sense in the context of moiré patterns. I was mostly thrown off by the fancy 3-D illustration in the article.
For anyone in a similar boat, here’s an image I found much more helpful:
For anyone in a similar boat, here’s an image I found much more helpful:
https://media.nature.com/w800/magazine-assets/d41586-018-078...
A picture, the right picture -- is worth a thousand words, as they say.
Thank you again for the link.