Ask HN: If I give an app permission to my photos, do they access to all of them?

My partner and I recently had our first child and we've opted to institute a 'no social media sharing' policy with any photos we share with our family and friends. But if they have granted apps, like Facebook and such, permission to access their photos, do these apps have access to all their photos or just ones that they've chosen to share?

One of the new privacy features in iOS 14 is the ability to limit an app’s access to specific photos instead of the ‘all’ or ‘none’ options that were previously available.

I believe this type of functionality is now available in Android 11 too.