Meaning of "synced extras" collection in LRC?

[dennisrfox]

A couple of months ago, after trying to figure out a separate syncing issue and re-syncing from LRClassic on my MacBook to LR on my iPhone, a collection appeared on LRC called Synced Extras with 2909 images. A few of these images are also on my phone, as they should be, but most are not, which is also correct. The file types in Synced Extras include jpg, heic, arw, cr2, and tif, and include ancient photos including scans, photos taken with a series of iPhones, as recently as just before the new folder appeared, and photos taken with other cameras.

Does this collection point to anything I should pay attention to, or can I just delete it?

[cmgap]

If this is a  Collection then they are virtual copies and you should be able to delete them without consequence. If you want to be sure, right-click  and choose Show in Library to identify where the original file is stored.

[dennisrfox]

Through another process I've since figured out what this was about. "Synced Extras" consists of photos I took with my iPhone, or which were on my iPhone earlier, that then synced back to my MacBook but were not in any of the Collections I was intentionally syncing.