Nope, that perfectly explains it, and is the kind of thing I was thinking it would be. It's just in my limited testing, I wasn't understanding exactly what was/wasn't causing the lights to show or not. But having an invisible light entity that needs to itself be covered by power to light totally makes sense.
When I first noticed this, I was thinking it had to do with using small electric poles vs mediums... but then I noticed even that wasn't completely consistent. Anyway, like I said it was just a curiosity and not a complaint.
Thanks for taking the time to explain!