Questions have arisen about the variety of diagrams and figures that are currently found in common use to represent triadic sign relations in Peircean semiotics. What do they mean? Which is best? Among the most popular pictures, some use geometric triangles while others use the sort of graph-theoretic diagram that Peirce used in his systems of logical graphs to represent triadic relations.
Diagrams and figures, like all signs, can be useful in communicating their intended interpretant signs and thus in coordinating attention to their intended objects, but only in communities of interpretation that comprehend their conventions of interpretation. Conventions of interpretation are, by comparison, far more difficult to communicate.
In that light, one of the prerequisites to the possibility of communication in this area would be to ask ourselves what are the conventions of interpretation enabling this species of diagrams and figures.