I would say the conceptual duality the paragraph is talking about is the duality of having imaginative and surreal vistas in one painting. Although what your referring to is a duality, I dont think it's what the paragraph is expressing. Hope that helps, Andrew

“But, how can imagination and surrealism have duality. They seem one thing.” Well, not one thing (in my opinion), but on the other hand, not exactly opposites either. I honestly have no idea what the writer is trying to say in the quoted text. I myself work with visual art, so I’m interested in what one can say meaningfully about it, but I often feel that people who write about art make very little sense. It’s like they just love to hear themselves talking - it doesn’t seem to matter to them that there is no real substance in what the say.