I think it’s maybe both.
I saw the patterns with the naked eye, so that’s presumably Moire with two layers of curtain material interfering.
The color fringes I think only showed up in the image, so that could be inteference with the sensor. I’ll check the next time the sun shines through there...
Thanks for the reply. I’m confused though. My reading of the Moire pattern is that it’s caused by two overlapping patterns which produce multiple slits that the light passes through, diffracts and interferes, producing an interference pattern? So Moire patterns are really interference patterns...