OK, so according to the documentation:
"Lightbox is a special type of collection that provides easy access to assets."
OK - so if I add images to my Lightbox, where can I see this Lightbox in AEM?
Assets -> Files choose file (tick) -> To Collection -> Add
Assets -> Collections -> Lightbox - view items present in collection
Sure - but how is the Lightbox collection different from any other collection, other than its private/unique only to the user?
You are correct, Lightbox uses LightBox API.
Both methods provided by this API provide assets for specific user only.
Thanks again Peter
From an API / Technical perspective this makes sense.
The business usage is a bit less clear - it looks like historically in CQ5, the lightbox API may have been used in Sites to allow users to select assets directly from their Lightbox. In AEM 6.4, it seems like it is more as a default personal collection
Unless there is some other business use case, I'll mark as closed