In 1968 McLuhan was in Tony Schwartz’s studio in NY with Harley Parker talking about art illustrations for Through the Vanishing Point.¹ Presumably they had an upcoming meeting in NY with Harper & Row, the publisher of TVP, to finalize its contents and layout. 

In a recording of the studio proceedings, McLuhan voiced a central problem regarding communication of his work:² 

I don’t know how to estimate the meaning of the fact that all the philosophers, all the scientists now living, are unaware that there is such a thing as visual space and that they have been living in it for 25 centuries and that is suddenly dissolving and leaving them — causing a considerable disorientation in their world. But how the hell do you start talking to these big shots and explaining the ABC’s of their world to them without creating an impression of megalomania or some utter nonsense?³

Also mentioned by McLuhan: the need for communications analysis to situate itself ‘beyond good and evil’…

I have no values as regards anything I talk about.⁴

Here are online⁵ pictures of the studio, the first with Tony Schwartz, the second with Schwartz, McLuhan and John Culkin. McLuhan looks surprisingly well after his brain tumor operation (mentioned in the recording), but he had obviously lost a lot of weight. The old Marshall looked more like Culkin in body style.