additional_images.php is missing:

PHP Code:
$GLOBALS 
on line 16

Bootstrap version of additional_images.php

PHP Code:
$zco_notifier->notify('NOTIFY_MODULES_ADDITIONAL_PRODUCT_IMAGES_START'); 
Default Zen Cart 1.5.6c version of additional_images.php

PHP Code:
$GLOBALS['zco_notifier']->notify('NOTIFY_MODULES_ADDITIONAL_PRODUCT_IMAGES_START') 
Is there a reason for this? Or is it just an error in the code?