Upshot: The eigenforms of Von Foerster, like the concept of invariants in ecological psychology, have proved useful in stimulating both theory and empirical work in the study of perceptually guided action. The target article offers a novel elaboration of the core idea of invariance in flux. I offer three sketches that suggest how the novel formalism might provide a useful stimulus to thought in specific domains: the use of names, Buddhist accounts of perception, and the sharing of experience in intense interpersonal interaction.