The presence of motion is increasingly common in online advertising. Despite the increase in spending on digital advertisements and decades of academic research on dynamic imagery in advertising, our understanding of this phenomenon remains limited. The dynamic default hypothesis posits that animated imagery should generate more arousal than comparable static imagery. However, research on advertisements containing dynamic imagery reveal inconsistencies in their ability to stimulate arousal. A potential explanation for these inconsistent findings lies in the behavioral urgency hypothesis, which postulates that not all motion is weighted equally in terms of its ability to generate arousal. We conduct three experiments to test this proposition. Interestingly, our findings show that imagery appearing to loom closer to consumers stimulates greater levels of arousal than either static or imagery appearing to recede away from consumers. Additionally, our work identifies moderating effects of lay rationalism which can work to strengthen or attenuate these effects. Together, this work provides a more comprehensive explanation for the varied findings in the literature.