diff --git a/src/applications/conpherence/controller/ConpherenceUpdateController.php b/src/applications/conpherence/controller/ConpherenceUpdateController.php
--- a/src/applications/conpherence/controller/ConpherenceUpdateController.php
+++ b/src/applications/conpherence/controller/ConpherenceUpdateController.php
@@ -79,6 +79,30 @@
               $user,
               $conpherence,
               $message);
+
+            // The above may generate multiple transactions.
+            // In practice, the comment is the only one.
+            $xaction_comment = PhabricatorTransactions::findByType(
+              $xactions,
+              PhabricatorTransactions::TYPE_COMMENT);
+
+            $text_metadata = $request->getStr('text_metadata');
+            if ($text_metadata && $xaction_comment) {
+              $text_metadata = phutil_json_decode($text_metadata);
+              $attached_file_phids = idx($text_metadata,
+                  'attachedFilePHIDs',
+                  array());
+              if ($attached_file_phids) {
+                $metadata_object = array(
+                  'remarkup.control' => array(
+                    'attachedFilePHIDs' => $attached_file_phids,
+                  ),
+                );
+
+                $xaction_comment->setMetadata($metadata_object);
+              }
+            }
+
             $delete_draft = true;
           } else {
             $action = ConpherenceUpdateActions::LOAD;
diff --git a/src/applications/transactions/constants/PhabricatorTransactions.php b/src/applications/transactions/constants/PhabricatorTransactions.php
--- a/src/applications/transactions/constants/PhabricatorTransactions.php
+++ b/src/applications/transactions/constants/PhabricatorTransactions.php
@@ -41,4 +41,19 @@
     );
   }
 
+  /**
+   * Find the first transaction that matches a type.
+   * @param array $xactions
+   * @param string $type
+   * @return PhabricatorTransaction|null
+   */
+  public static function findByType($xactions, $type) {
+    foreach ($xactions as $xaction) {
+      if ($xaction->getTransactionType() === $type) {
+        return $xaction;
+      }
+    }
+    return null;
+  }
+
 }