Did you read the article? The code sections show the player_name and position variables being synced with the position being synced every 16ms/62.5Hz.

The sentence right before your first quote answers your question -

"Note that the client code doesn't "instantiates" the scene explicitly. However, since the scene is marked for replication [... your quote]"

In this case its sending the scene for the clients to instantiate.

They gave an example of messaging as well - RPC.