Chris Crawford's two chapters generally discuss about interactivity in two ways: speaking how it's been horribly misused and throwing questions about if it's whether subjective to put labels of "high" or "low" interactivity. According to his words, the refrigerator interacts with the user at a "low level." Overall, he says that interactivity is like a good conversation and must have three elements of listening, thinking and speaking. His diverse views and opinions are interesting, yet the overuse of metaphors and monologues rather makes an already unclear topic to be more confusing until the forth section of Chapter 1. Especially, he often mentions about how interactivity can't be subjective. However, his reference about "the greatest movie in the world can lose our attention to the sound of munching popcorn" or "our involvement with a great book will surrender itself to a buzzing fly" isn't completely convincing to me in a sense that depends on the type of audience or circumstances, "a buzzing fly" can demolish one's concentration towards a great book.
On another hand, Bret Victor's "little rant" is simple and straight to the point. It also has more legibility for readers than the previous reading - due to its minimal page structure that excludes any other information and well accompanying images and videos. Also, the fact that the second reading doesn't requires the access of complicated and slow NYU library system, made me think about how design and technology act like life vessels to interactivity, although they might not be the interactivity itself. Bret Victor's main focus is on the relationship of human capabilities and a tool. When he was comparing "pictures under glass" with technology, it reminded me of Material Design and what it aims to be: creating a visual language that synthesizes "classic" principles of good design with the innovation and possibility of technology and science.
What people is seeking for is not always new, high-tech and trendy interactivity but their interest rather lies on instincts and trained psychology. My generation's and the prior ones' long history of reading on paper surface and drawing with pencils - those are the examples that current digital products try to mimic "under glass." It suggests another answer why definition of interactivity has been changing, and has to be continuously changing, because people's lifestyle and habits are altering as well.
Assuming that this whole question is based on the "automated interactivity - interactivity effected by means of computing machinery", I will define physical interaction as the communication and core connection between human and machine - and a good physical interaction is generated by wise choices of design and technology that understand the audience. Based on Chris Crawford's view that interactivity is a conversation, I would say some examples of digital technology that are not interactive are 3D movie and VR ride because although they drag users' reaction, they don't necessarily listen to them or speak back; while VR game, which sounds similar with VR ride, can be interactive because it results clear transaction of input and output.