More by accident I finally found out what this is four.
If you are on a flight where you wan buy a potential business upgrade in Europe, you can do it with that functionality. This is however only shown if you are on flight which is eligible for the upgrade.

This functionality seems to be targeted at travel agents - it would seem that the manual process on the normal booking systems was pretty complicated.

More info can be found here:


http://www.swiss.com/web/EN/various/...Upgrade_DE.PDF