I recently purchased extra storage for my iCloud account. I've set up family sharing and wanted to know if I would be able to see photos that my family is syncing, and vice versa...would they be able to see photos that I've synced?
iPhone X, iOS 12
No. See the following from Share an iCloud storage plan with your family - Apple Support
When you share a storage plan, your photos and documents stay private and everyone keeps using their own accounts with iCloud—just like when you have your own storage plan. You simply share the space available in the iCloud storage plan with your family members, so you only have one plan to manage.
If you want to share photos, you can do that with a shared album: Use Shared Albums in Photos - Apple Support
No. See the following from Share an iCloud storage plan with your family - Apple Support
When you share a storage plan, your photos and documents stay private and everyone keeps using their own accounts with iCloud—just like when you have your own storage plan. You simply share the space available in the iCloud storage plan with your family members, so you only have one plan to manage.
If you want to share photos, you can do that with a shared album: Use Shared Albums in Photos - Apple Support
iCloud Storage Question
