After completing a transaction on a Worldpay hosted payment page, Worldpay sends a response to the Payment Response URL specified in the installation settings (eg example.com/thankyou.php).
The only way I've found to keep the user on the originating website is to use a meta-refresh on the Response URL page (as per Worldpay docs). Without the meta-refresh, the user remains on Worldpay's site and is shown their default thank you page.
What is the technical purpose of performing a meta-refresh? Is it to send a 200 header response back to Worldpay?