diff --git a/flutter/lib/common.dart b/flutter/lib/common.dart
index f5ebca3b7..d3d94baa2 100644
--- a/flutter/lib/common.dart
+++ b/flutter/lib/common.dart
@@ -1543,6 +1543,9 @@ Future<bool> restoreWindowPosition(WindowType type,
   bool isRemotePeerPos = false;
   String? pos;
   if (type == WindowType.RemoteDesktop && windowId != null && peerId != null) {
+    // If the restore position is called by main window, and the peer id is not null
+    // then we may need to get the position by reading the peer config.
+    // Because the session may not be read at this time.
     if (desktopType == DesktopType.main) {
       pos = bind.mainGetPeerFlutterConfigSync(
           id: peerId, k: kWindowPrefix + type.name);
diff --git a/src/flutter_ffi.rs b/src/flutter_ffi.rs
index d0106ae54..4a12ee19f 100644
--- a/src/flutter_ffi.rs
+++ b/src/flutter_ffi.rs
@@ -806,6 +806,8 @@ pub fn main_get_peer_option_sync(id: String, key: String) -> SyncReturn<String>
     SyncReturn(get_peer_option(id, key))
 }
 
+// Sometimes we need to get the flutter config of a peer by reading the file.
+// Because the session may not be established yet.
 pub fn main_get_peer_flutter_config_sync(id: String, k: String) -> SyncReturn<String> {
     SyncReturn(get_peer_flutter_config(id, k))
 }