Previous studies at the intersection between rendering and psychology have concentrated on issues such as realism and acuity. Although such results have been useful in informing development of realistic rendering techniques, studies have shown that the interpretation of images is influenced by factors that have little to do with realism. In this paper, we summarize a series of experiments, the most recent of which are reported in a separate paper, that investigate affective (emotive) qualities of images. These demonstrate significant effects that can be utilized within interactive graphics, particularly via non-photorealistic rendering (NPR). We explain how the interpretation of these results requires a high-level model of cognitive information processing, and use such a model to account for recent empirical results on rendering and judgement.