Thank-you for the idea.
I did have a short explanation in the alt-text, which I'll repeat here with some clarification: they are the three arrows (as in: from a [cross]bow) to strike at the heart of ideologies against peoples' self-determination: capitalism, monarchism, and vanguardism [eg. Soviet communism].
It's a symbol that's used by antifascists, socialists, anarchists, and left-leaning social democracts.
EDIT: It's a very good thing you asked. Asking questions makes us all smarter :)
I'm sure there are alternative user-interfaces more suitable for your favourite form of GUI navigation, but alas I wouldn't be the right person to ask for help.
But I'll repeat that I'm very happy I was asked for clarification. There's certainly more than one person who for one reason or another left my alt-text unread.