As I mentioned below, I've followed this from the beginning. I was reading the Podesta emails and following discussion in r/dncleaks when this stuff started popping up in there. I suppose it may have started on one of the chans first, I don't know. The "code words" list had the feel of an expert in the memetic arts.
Anyway, I think you're right, it was the art of Tony Podesta and Alefantis that triggered a lot of people over. There was that one article about Podesta's collection mentioning the art photos of naked teens in his house where they took glee in the fact they shocked guests. Having been around art people a lot, I certainly understand the desire to provoke. Sometimes people will get provoked. You get different reactions outside the bubble.