diff --git a/app/lib/entity/file/repo.dart b/app/lib/entity/file/repo.dart
index 6ccdc9c1..65db5298 100644
--- a/app/lib/entity/file/repo.dart
+++ b/app/lib/entity/file/repo.dart
@@ -10,6 +10,8 @@ part 'repo.g.dart';
 abstract class FileRepo2 {
   /// Query all files belonging to [account]
   ///
+  /// Returned files are sorted by time in descending order
+  ///
   /// Normally the stream should complete with only a single event, but some
   /// implementation might want to return multiple set of values, say one set of
   /// cached value and later another set of updated value from a remote source.
@@ -127,6 +129,8 @@ class CachedFileRepo implements FileRepo2 {
 
 abstract class FileDataSource2 {
   /// Query all files belonging to [account]
+  ///
+  /// Returned files are sorted by time in descending order
   Stream<List<FileDescriptor>> getFileDescriptors(
       Account account, String shareDirPath);
 
diff --git a/app/lib/widget/collection_browser/bloc.dart b/app/lib/widget/collection_browser/bloc.dart
index c9b76c73..d51da1da 100644
--- a/app/lib/widget/collection_browser/bloc.dart
+++ b/app/lib/widget/collection_browser/bloc.dart
@@ -501,18 +501,24 @@ class _Bloc extends Bloc<_Event, _State> with BlocLogger {
     );
   }
 
+  /// Remove file items not recognized by the app
   List<CollectionItem> _filterItems(
       List<CollectionItem> rawItems, Set<int>? whitelist) {
     if (whitelist == null) {
       return rawItems;
     }
-    return rawItems.where((e) {
+    final results = rawItems.where((e) {
       if (e is CollectionFileItem) {
         return whitelist.contains(e.file.fdId);
       } else {
         return true;
       }
     }).toList();
+    if (rawItems.length != results.length) {
+      _log.fine(
+          "[_filterItems] ${rawItems.length - results.length} items filtered out");
+    }
+    return results;
   }
 
   String? _getCoverUrlByItems() {