IS PHAsset image unique globally for all iPhones?

Question

When fetching images using the Photo framework, I am getting all images of the gallery from the PHAsset object. My question is if the images from PHAsset are globally unique or are they device specific. Can I use the same PHAsset image on different iPhones? i don't want to convert the UIImage to NSData and convert it again from NSData to UIImage.

PHFetchResult *smartAlbums = [PHAssetCollection fetchAssetCollectionsWithType:PHAssetCollectionTypeSmartAlbum subtype:PHAssetCollectionSubtypeAlbumRegular options:nil];

//set up fetch options, mediaType is image.
PHFetchOptions *options = [[PHFetchOptions alloc] init];
options.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
options.predicate = [NSPredicate predicateWithFormat:@"mediaType = %d",PHAssetMediaTypeImage];

for (NSInteger i =0; i < smartAlbums.count; i++) {
    PHAssetCollection *assetCollection = smartAlbums[i];
    PHFetchResult *assetsFetchResult = [PHAsset fetchAssetsInAssetCollection:assetCollection options:options];

    NSLog(@"sub album title is %@, count is %ld", assetCollection.localizedTitle, (unsigned long)assetsFetchResult.count);
    if (assetsFetchResult.count > 0 && ![assetCollection.localizedTitle isEqualToString: @"Recently Deleted"]) {            

        for (PHAsset *asset in assetsFetchResult) {
            PHImageRequestOptions *option = [PHImageRequestOptions new];
            option.synchronous = YES;

            [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:CGSizeMake(self.view.frame.size.width, self.view.frame.size.height-100) contentMode:PHImageContentModeAspectFit options:option resultHandler:^(UIImage * _Nullable result, NSDictionary * _Nullable info) {
                [mutArrAsset addObject:asset];

                [self.imagesURLArray addObject:result];
            }];

            NSLog(@"asset are %@", asset);
        }}}

Answer 1

A PHAsset represent a pointer to an image in the user's photo library. People have different images on their phone so it doesn't make sense to pass that pointer to a different phone. PHAsset 's id is explicted called localIdentifier for this reason.

If you want to transfer an image from one device to a different device you have to transfer it as NSData .