The one I don’t* understand is the “top left” part of the X. But then physics was so long ago.
… the years I’ve lived here, I’ve come to know lots of ways the light plays through the house at various times of day or year. Although it’s late October, I’m still finding it necessary to slant the blinds to deter sunlight in the afternoon, in order to avoid needing to run the A/C. I guess I just had one slat out of place, creating a shaft of light way over in the dining room and out the back door, and reflecting back inside to make an X. Never seen this one before and likely won’t again…
Skyscapes for the Soul - Jeni Bate 