I found this very confusing.
I see you are going for the Thing Explainer style a la XKCD. That only works for a subset of learners.
A major hurdle is that you jump right in to “imaginary devices”. And these imaginary devices are rolling marbles of all things.
Perhaps a better way would be a historical look at how communication evolved. Smoke Signals, Flags on Ships, Telegraph, Radio, Switching Telephone, Packet Telephones
These are concrete things people can see and grok.
See “Don’t make me think” book. The essence is that “imaginary devices” is super effortful for the reader and hampers the gradual learning for beginners to acquire the knowledge