The order panel and the contact form both send the same three things: the name you type, the contact you type, and the message — which, on the panel, is the order tape you built plus any note you added. Nothing else is read from your browser and sent anywhere.
The form posts to a small script on this domain. That script also reads the IP address the request came from and the time it arrived, puts both in the email so an obvious flood is recognisable, and uses the address to cap how many messages one address can send in an hour. A hidden setting sits in the form to catch automated submissions; if it is filled in, the message is discarded.
Two things stay in your own browser, and only there. After the opening sequence has played once, the page notes that fact under the key wt-power in session storage, so it does not replay on every page you open. And as you throw the switches on the order panel, the rail along the bottom of the screen keeps the six lamp states under the key wt-lamps — six letters, one per bank — so the rail still shows your order after you move to another page. Neither is a cookie, neither is ever sent to us, and closing the tab clears both.