This page lists image files found in the item photo storage directory that are not currently linked to any item in the database — typically left behind after an item was deleted or its photo was replaced.
You can review the unlinked files and select Delete selected to remove just the ones you choose, or Delete all to clear all of them at once and reclaim disk space.
Deleting a photo file here only removes the orphaned image on disk; it does not affect any item currently in your inventory.