Researchers have identified challenges students face when modeling dynamic situations. This report discusses the results of semi-structured clinical interviews with ten prospective secondary mathematics teachers who were provided with a dynamic image of a growing and shrinking cone. We asked the students to graph the relationship between the surface area and the height of the cone. We identify four themes in the students' solution approaches and discuss the implications of these approaches. Specifically, we discuss the themes with respect to relationships between the students' solutions and their images of the growing and shrinking cone, including the extent that they leveraged this image to determine their solutions. [For the complete proceedings, see ED583989.]