The sideways Jacob's Ladder is a marvelous thing. I assume that the arc travels to the left because the two lines are suspended in such a way that the gap between them is less at the left. Each arc appears to be struck by the conductive surface path on the pole to the right.
It's luck that the geometry conspired to produce this effect. You would have some work to attempt to recreate it.
And no, it didn't trip a breaker because it's just another electrical load, like a really big fluorescent lamp, which works on the same principle.