The discussion centers on the ambiguity of the term "spatial dimensions" in relation to a plot, questioning whether it refers to the xy, xz, or yz plane. Participants suggest that "spatial dimensions" typically denote left-right and down-above distances on a graph, which often represent specific variables like time and population. There is a call for visual clarification, indicating that a picture of the plot would enhance understanding. The conversation highlights the need for precise definitions in data visualization discussions. Clear communication is essential for interpreting spatial dimensions effectively.