Situated ideas

An idea is an idea is an idea. Or is it?  If ideas can be understood as elements of thought that can be either abstract, concrete or visual, is design ideation situated in any particular element of thought? Although design is often thought of in visual terms, as expressed in, for example, 2D and 3D images, graphs, prototypes or models, design can also be articulated in the abstract, say design theory or programming, or in concrete terms, in which the idea has physical referents. So what seems to matter in design ideation is that the idea is not localised in any particular element of thought but that which best expresses the essence of the idea, and be it in the context of, say function, styling or production.