I take part in the Tour de Zwift. My friends want to look at the side race and support me. Currently, there is no such function.
If they have Zwift they can log in and follow you that way.
Alternatively, you could stream the race from your perspective.
Currently there aren’t really any other good spectator tools. That might change with the recent developments with Zwift’s support of eSports and KISS.
“a complete Zwift eRacing product launch [is] expected in 2020” according to ZwiftInsider and TriRadar. That should definitely come with spectator tools. (e.g. something like Blizzard trialled with the Overwatch League recently)
This is a very simple tool and it does not work correctly. You can turn on the preview if you are standing close to the cyclist. If you stand far, it will not switch your view!