I used Personal Backup to synchronize my Photos folders and now the files are mixed up? What did I do wrong?
We don't recommend that you use the synchronization function of Personal Backup with Photo folders.
Photos uses a very unique naming convention - Apple suggests that you never modify the contents of your Photos folder.
Apple recommends to use Photos to delete, duplicate, or modify any photos in the Photos library. Modifying the contents of the Photos library from anywhere but the Photos application could result in a library that is unusable and may cause photos and albums to no longer appear in Photos."
Instead of using the synchronization function of Personal Backup with Photos folders you should use the BACKUP function to make a backup of your photos to another drive - in case image files become unusable or unintentionally erased from your hard disk.