Photos

It's not clear what you mean by "backed up," so I'm going to guess that you mean "after they are synced with iCloud." The reason for saying it that way is that iCloud isn't a backup service.

When you make a backup, it's there in case you mess up, maybe mistakenly erasing pictures that you wanted to keep. So a backup is static (like you implied in your question) and never changes. That way you can go back and restore those mistakenly erased pictures. That isn't what iCloud does.

iCloud is a synchronizing service-- it makes sure that the pictures in your iPhone, in your iPad, and on your Mac are all the same. So when you edit a picture on your Mac, for instance, the change is made on your phone and everywhere-- keeping them all the same.

So that's the answer to your question, if you're asking about iCloud. With iCloud syncing service all the pictures change together. But be careful! If you erase a picture on your phone, for instance, it will be erased everywhere! You can't ever get it back! (Well, for 30 days it goes into the Recently Deleted folder, unless you force it to erase.) iCloud doesn't backup your pictures. Most of us use Time Machine or some other system to periodically backup our Photos Libraries.