product description on delivery note/packing_slip

Hi, i was trying to use

add_action( 'wpo_wcpdf_after_item_meta', 'wpo_wcpdf_show_product_description', 10, 3 );
function wpo_wcpdf_show_product_description ( $template_type, $item, $order ) {
    if (empty($item['product'])) return;
    if ( $template_type == 'packing_slip') {
        $_product = $item['product']->is_type( 'variation' ) ? wc_get_product( $item['product']->get_parent_id() ) : $item['product'];
        if ( method_exists( $_product, 'get_short_description' ) ) {
            $description = $_product->get_short_description();
            printf('<br><div class="product-description" style="font-size: 9px;">%s</div>', $description );
        }
    }
}

to show product descriptions on the delivery note (first question: what is your translation of the german “Lieferschein”? packing_slip or delivery_note?) Without the restriction the code is working fine. On packing_slips/delivery_note and invoices. With the restriction no description on the packing_slip/delivery_note. I was trying packing_slip and delivery_note in the code.

In german there is Packliste (packing_slip?) and Lieferschein (delivery_note?). Please pardon my confusion.