link to source - if it's on the display page link to original source (probably on a different site). All other conversations link to 'llink' which is a local copy and may provide a richer possibility of interactions, especially if you're logged in locally and it's your own copy of the post.

include/conversation.php

@@ -690,7 +690,7 @@ function conversation(&$a, $items, $mode, $update, $page_mode = 'traditional') {
 					'owner_name' => $owner_name,
 					'owner_url' => $owner_url,
 					'owner_photo' => $owner_photo,
-					'plink' => get_plink($item),
+					'plink' => get_plink($item,$mode),
 					'edpost' => false,
 					'isstarred' => $isstarred,
 					'star' => $star,