In his universe, both the interstellar net and combat links between ships are low bandwidth. Hence, video is interpolated between sync frames or recreated from old footage. Vinge calls the resulting video "evocations".
The plot point being that when the bandwidth gets too low, the interpolation AI has to make lots of stuff up, you are not quite sure exactly what was said.
I seem to remember the bandwidth in the book was very tiny, small number of bits per second (?) so the AI was taking the speech and compressing it into something more compressed than text then decompressing it at the other end into something that was more or less the same.
It has a very very cool twist to explain the Fermi Paradox and is a really good example of a universe with one modified rule.
I believe this is huge and would create higher engagement if everybody was acutally looking into the camera instead of to the side or up all the time. Creating a more human an emotional relation with the people you are talking to.
https://techxplore.com/news/2019-06-intel-eye-contact-video-...