It took me a while to figure out that the English mispronunciation of “Heil” rhymes with a certain imitation of a newspaper.
Anyway, this time, they seem to be right.
Van der Bellen was the leader of the Austrian Green party from 1997 to 2008. That’s a left-wing/progressive party; their supporters would universally identify as “lefties”. They usually don’t get beyond 15%. Van der Bellen ran as an independent candidate, and reached out far beyond his party’s traditional voters, but I assume that the people depicted cheering at his official supporter’s party were mostly left-wing supporters. And OF COURSE WE’RE GLOATING!