Consumers’ product purchase decisions typically involve comparing competing products’ visual features and functional attributes. Companies strive for “product differentiation” [1-5], which makes consumers’ product comparisons fruitful but also sometimes challenging. Psychologists that study decision-making have created models of choice such as the cancellation-and-focus (C&F) model. C & Fexplains and predicts how people decide between choice alternatives with both shared and unique attributes: the shared attributes are “cancelled” (ignored) while the unique ones have greater weight in decisions. However, this behavior has only been tested with text descriptions of choice alternatives. To be useful to designers, C&F must be tested with product visuals. This study tests C&F under six conditions defined by: the representation mode (text-only, image-only, and image-with-text) and presentation (sequentially, or side-by-side) of choice alternatives. For the products tested, C&F holds for only limited situations. Survey and eye-tracking data suggest different cognitive responses to shared text attributes vs. shared image features: in text-only, an attribute’s repetition cancels its importance in decisions, while in images, repetition of a feature reinforces its importance. Generally, product differences prove to attract more attention than commonalities, demonstrating product differentiation’s importance in forming consumer preferences.