code: protected function getTemplateVariables($recipient, $config, $pages)
      {
          return [
              'Subject' => $config->ReviewSubject,
              'PagesCount' => $pages->count(),
              'FromEmail' => $config->ReviewFrom,
              'ToFirstName' => $recipient->FirstName,
              'ToSurname' => $recipient->Surname,
              'ToEmail' => $recipient->Email,
          ];
      }
docs: Gets list of safe template variables and their values which can be used
  in both the static and editable templates.
  
  {@see ContentReviewAdminHelp.ss}
  
  @param Member     $recipient
  @param SiteConfig $config
  @param SS_List    $pages
  
  @return array