Looks like the Pirate Party’s gain in seats came out at the Progressive’s expense. Seems people there want their leftism more anarchist than totalitarian.
Words like “progressive” often mean different things in the politics of different countries. In Iceland, the Progressive Party is an agrarian and populist-type center-right party.
It has, over the years, evolved from a center party to a center-right party. Formerly, it sometimes joined with left-of-center parties to form a government, and sometimes with right-of-center parties. Nowadays, it is firmly center-right. For a time, it joined with the center-left in being open to joining the EU. Today, it is definitely opposed to EU membership.