From using my app on iOS 14 it appears the way it works is based on you accessing the photos library. So it goes like this: Initial launch - user chooses a few

From using my app on iOS 14 it appears the way it works is based on you accessing the photos library. So it goes like this: Initial launch - user chooses a few photos. User switches apps, and returns - the same photos are selected. User force quits app (or doesn't use app for a few days and it gets killed off) User opens app, and is then prompted whether they want to "Keep Current Selection" or "Select More Photos" the first time the app accesses the photo library in some way (I think this is based on when you do a photo permissions check, but not positive.) #3 has existed since the iPhone added apps - UIImagePickerViewController - if you use it, you don't need photo permissions and you only get access to the photo the user selected. Most social media apps probably just skip using this because they want photos permission everywhere to do things like "post latest photo" or to show their own photo picker UI.