diff -u b/src/DiffEntityComparison.php b/src/DiffEntityComparison.php
--- b/src/DiffEntityComparison.php
+++ b/src/DiffEntityComparison.php
@@ -270,29 +270,52 @@
   public function getRevisionDescription(ContentEntityInterface $revision, ContentEntityInterface $previous_revision = NULL) {
     $auto_generated = FALSE;
     $revision_summary = [];
+    // Check if the revision has a revision log, if not the auto generate it.
     if ($revision instanceof RevisionLogInterface) {
       $revision_summary = Xss::filter($revision->getRevisionLogMessage());
-      if ($revision_summary == '' && $previous_revision) {
+      if ($revision_summary == '') {
         $auto_generated = TRUE;
         $revision_summary = [];
       }
     }
-    elseif ($previous_revision) {
+    else{
       $auto_generated = TRUE;
     }
     if ($auto_generated) {
-      $left_values = $this->summary($previous_revision);
-      $right_values = $this->summary($revision);
-      foreach ($right_values as $key => $value) {
-        if (isset($left_values[$key]) && $value != $left_values[$key]) {
-          $revision_summary[] = $value['label'];
+      // If there is a previous revision, load the values of each and add to the
+      // summary the ones that have changed.
+      if ($previous_revision) {
+        $left_values = $this->summary($previous_revision);
+        $right_values = $this->summary($revision);
+        foreach ($right_values as $key => $value) {
+          // If the field is present in the left entity, compare values, if not
+          // add it to the summary. Unset the ones already added.
+          if (isset($left_values[$key])) {
+            if ($value != $left_values[$key]) {
+              $revision_summary[] = $value['label'];
+            }
+            unset($left_values[$key]);
+          }
+          else {
+            $revision_summary[] = $value['label'];
+          }
+        }
+        // Loop over the left values that remain and add them if not present in
+        // the right entity.
+        foreach ($left_values as $key => $value) {
+          if (!isset($right_values[$key])) {
+            $revision_summary[] = $value['label'];
+          }
+        }
+        if (count($revision_summary) > 0) {
+          $revision_summary = 'Changes on: ' . implode(', ', $revision_summary);
+        }
+        else {
+          $revision_summary = 'No changes.';
         }
-      }
-      if (count($revision_summary) > 0) {
-        $revision_summary = 'Changes on: ' . implode(', ', $revision_summary);
       }
       else {
-        $revision_summary = 'No changes.';
+        $revision_summary = 'Initial revision.';
       }
     }
 
only in patch2:
unchanged:
--- a/src/Tests/DiffRevisionTest.php
+++ b/src/Tests/DiffRevisionTest.php
@@ -73,7 +73,7 @@ class DiffRevisionTest extends DiffTestBase {
     $this->assertEqual(count($rows), 2);
     // Assert the revision summary.
     $this->assertUniqueText('Revision 2 comment');
-    $this->assertText('No changes.');
+    $this->assertText('Initial revision.');
 
     // Compare the revisions in standard mode.
     $this->drupalPostForm(NULL, NULL, t('Compare'));