How does the nitrogen infusion work in the NESCAFÉ Azera Nitro cans?

In the cans liquid nitrogen is added to the liquid coffee in the can. The can is then seamed and the liquid quickly becomes gas in the available space between the coffee and the can. After this, the can is inverted and nitrogen is charged into the widget at the bottom of the can. At this point, the majority of the nitrogen is within the widget but there will still be some remaining in the headspace.