Answer, part 2.
According to the writer:
Pettibon combined his picture with an apropos quotation that captures that experience.
Google also tells me that the quotation itself is from Henry James--from a volume of his autobiography entitled "The Middle Years."
Henry James, 1843-1916, is considered a great writer, but personally I have never been able to read him. He is famous for writing long, convoluted, hard-to-understand sentences.
"I have, I confess, truly to jerk myself with violence from memories and images, stages and phases and branching arms, that catch and hold me as I pass them" means that his memories are like something with "branching arms that catch and hold me," perhaps like thorny bushes, or trees in a dense jungle. He gets stuck in each vivid memory, and he to "jerk myself with violence" from each one in order to get to the next one and create a coherent narrative.
So, Henry James was trying to make sense of tangled, vivid flashes of memory, so his quotation makes sense when we are looking at a mysterious and powerful picture and getting tangled, vivid, partial flashes of insight.
It would certainly help if we had the actual Pettibon picture to look at. I couldn't find it but perhaps this one is somewhat similar: