function events_preprocess_node(&$variables) {
  // Get route name.
  $routeName = \Drupal::routeMatch()->getRouteName();
  // Get entity.
  $node = &$variables['node'];
  // Check if it's an event.
  if ($node->getType() === 'event' && $node->hasField('field_place')) {
    // Get the place.
    $place = $node->get('field_place')->entity;
    // Check if place is NULL.
    if ($place) {
      if ($node->get('field_teaser_media')->isEmpty()) {
        // Get teaser.
        $variables['place_teaser_media'] = $place
          ->get('field_teaser_media')
          ->view($routeName === 'entity.node.canonical' ? 'default' : 'small_teaser_square');
      }
      // Get organization name from place.
      $variables['place_organization'] = $place
        ->get('field_address')[0]
        ->get('organization')->getValue();
    }
  }
}