Drupal 7, Drush. Bulk update changed time for specific product displays using drush

update_product_displays.drush

<?php
// drush php-script update_product_displays.drush

$time = time();
$prev_timestamp = $time - (15 * 60);

$efq = new EntityFieldQuery();
$efq
  // Conditions on the entity - its type and its bundle ("sub-type")
  ->entityCondition('entity_type', 'node')
  ->entityCondition('bundle', array('product_with_palette', 'product_display'))
  ->propertyCondition('changed', $prev_timestamp, '<');

// Execute, returning an array of arrays.
$result = $efq->execute();

// Ensure we've got some node results.
if (!isset($result['node'])) {
  drush_log("No nodes to process.", "ok");
  return;
}

// Iterate over the result, loading each node at a time.
foreach($result['node'] as $nid => $stub_node) {
  // Load the full node and wrap it with entity_metadata_wrapper().
  $node = node_load($nid);
  $node->changed = $time;
  node_save($node);

  // Log our progress.
  drush_log("Processed nid={$nid}", "ok");
}