I don't know what to call this and want to know how it's done

Hi All, I just saw something way too cool, just have no idea what to call it.

If you do php and javaScript with AJAX, you will be amazed, and I really want to know how this is done.
Here is the (demo) website,
http://www.tag.powa.com/product/SS13-FR183-GREYENDONEND/Lightweight+End-on-End+Single-Breasted+Jacket (this is the site to use your app on.)

My friend pointed his Iphone at the qr code and took a picture. The website actually responded immediately and an AJAX processing .gif replaced the qr code.
He entered a pin and the transaction was complete and the website then displayed the “thank you for your purchase” page.
(they actually manipulated an individual web page viewed by me and photographed by me from an app)

http://www.youtube.com/watch?v=OyHjPVsY0UQ&feature=youtu.be is how it works.
in the first few seconds watch as she makes a purchase by taking a picture of the qr code and note how the website reacted with a processing gif.

What I think I know,
The barcode is generated randomly by javascript, it changes on every page load.
NOTE: If you submit the barcode to a reader, all you get is the URL and no random (extra) code.

The site sets two cookies, JSSID and svrtkn but I would suspect that a div would have an identifying string to do the AJAX update but it does not.

I Know AJAX and don’t understand this.

Stay with me.
The app. on the iphone (unless smarter than me) will send the photo data to something like tag.powa.com/appdata.php
My huge question is, how does a request (POST or GET) to appdata.php change the page “you” are viewing.
I know how to deal with any kind of incoming data but this is AJAX with an external request.

Something tells me this is the future.
Please help me understand this.

I have more info, ask me or run this yourself. On the link, what’s this has a link to the Iphones app center

Thanks and hope to hear some speculation

You don’t know whether the user previously tied together the mobile device and computer (using Unique ID of each) through an account.
I that way the the current computer session can be identified by the ID of the device and linked - as we see in the initial part of the video.

My guess is websockets. I don’t know much about it but I believe it can be done that way. With websockets the server can push data to the browser. In this case, only to the one browser listening for something about the unique ID embedded in that QR code.