This paper reports on a study using diorama constructions made by 13–14-year-olds who have been studying the topic of climate science. A diorama is a model representing a scene with three-dimensional structures, usually in miniature. The building and interaction of diorama is not the norm for students to represent their thinking of sustainable communities, however there is growing interest in representational work and multimodal reasoning which provide a springboard for scientific play, dialogue, and agency. Using a micro-ethnographic approach informed by socio-semiotic perspectives with the research of Lemke (2004), this study aimed to explore how diorama construction and the associated interaction can contribute to student reasoning and learning. Data were generated using audio recorders and multiple cameras, tracking groups of students negotiating their visual representations. The analysis proceeded through active and iterative viewing of audio and video recordings, followed by identification of themes to establish possible relationships between construction and reasoning. Through this process, the study (a) identifies multiple, necessary conditions and varied opportunities for students to enact and enable reasoning, and (b) extend current understanding of how the affordances of this visual mode interact with these conditions to contribute to student learning of climate science.