Frankly, this is a genius move. Virtual cards have been around for a long time, but they have been a hassle. By embedding them directly in a browser, it lives right where the user needs them. I wonder how long it takes before Apple implements a similar solution for ApplePay, making Apple Pay a viable solution everywhere you see a credit card input.
Truth be told, Vipps could also implement a browser plugin doing the same: implementing a new virtual card every time it detects a card input in your browser. This would be an elegant solution to control the whole payment infrastructure without dealing with every merchant.