Well. I guess it self-resolved. Nevermind! For any of you interested, the code that stuck was:
$attachments = get_children( array(
'post_parent' => $attr['id'],
'post_status' => 'inherit',
'post_type' => 'attachment',
'post_mime_type' => 'image',
'order' => $attr['order'],
'orderby' => $attr['orderby'],
) );