The visual illusion Terror Subterra, by Roger Shepard (1990), depicts a seemingly large creature chasing another in a tunnel, yet both creatures are physically identical. In addition to this visual illusion, the two creatures also appear to exhibit different emotions, as the background creature (the pursuer) appears angry whereas the foreground creature (the pursued) appears fearful. We explored this context effect by first establishing the magnitude of the emotional bias effect. We then modified the original drawing in various ways, such as equating for perceived size, removing one creature from the scene, and removing the pictorial context altogether. Findings suggest that the emotional bias is due to the pictorial setting and to the perceived social-emotional relationship between the two creatures. These results highlight the importance of both perceptual and social-emotional influences in driving affective attributions.