It is a half-joke. In the sense that it is something I basically believe, but stated in a way that neglects nuance to the degree to which it might tip over into false-ness.

Baby pictures, I don’t think they communicate much. They evoke feelings that are already in the mind of the viewer.

I mean, it is basically a universal experience, to be shown pictures of other people’s kids and nod along understanding that they are justifiably excited about the objectively boring things their kids are doing, right? This is because they are excited about the ongoing journey that picture acts as a landmark for, which we aren’t a part of.

So, I suppose there must an example of an image that communicates something useful out there, somewhere, but the two of us haven’t found it yet.

CAD is a stronger example (once you get to any practical complexity, naming the entities becomes intractable (and you need names to form text sentences about them), spacial selection is much more effective, even with hierarchical grouping of parts.)

Though even for text-based development, it's worth looking at Bret Victor's "inventing on principle" talks - it's more about the discrete vs continuous boundary (and that more things are honestly continuous than you might assume.)