Never having clapped eyes on this before, it seems like the polymer hosing's primary feature is to allow light in.

However, it being positioned directly beneath dense foliage, I can't quite understand it ?

Have you ever looked at it late at night when the light would be on? Lights like that are placed all around botanic gardens and even in public gardens around Chicago. There are beautifully lit up twisted hawthorne trees in the Art Institute gardens. They create a very nice walking experience, not meant to highlight a tree but more of a mood lighting and just enough to light the paths up to walk safely.

I didn't think that it would emit light, only that it would absorb.

Of course, that makes perfect sense !

This a little farther than I usually stray, so I not having seen it before, anywhere.

My initial hunch was correct; after returning this October evening I found no light emitted and from the home owner themselves was told that its primary purpose was indeed to absorb light.

Absorb light for what purpose? Is it connected to some solar powered device? Or is it just an opening to let a bit of light into a dark basement? Really weird placement in either case! Thanks for the update on it.

I didn't pursue the matter, as the owner thought it odd.

However, she let slip that the light would pass through, so I assume it to illuminate the downstairs area.