Now you've made me curious. The depths of the interwebs reveal that she says she casts an empty ballot, no reasoning given. Iceland doesn't have compulsory voting.

Staying in Iceland: Jón Gnarr is also an anarchist and ran for office. Then, I'm an anarchist and the opposite of anti-electoral, if nothing else it's necessary to combat depoliticisation and protect liberal democracy as the stopgap measure it is. Fascists won't stop voting to try and capture the state least you can do is cancel out their vote by voting non-fascist.

I'm not even sure there's many anti-electoral anarchists around, actually arguing against voting instead of simply personally not voting (which lots of people do for various reasons), practically all the arguments you hear from that side is egg-headed theoretical moralising without reference to praxis.