No different than syncing to a server. Many video calls are implemented with p2p up to a certain amount of participants. Text is less demanding in comparison. I’ve not dived into the code yet but p2p relays typically just coordinate what IPs need to connect. In your case, once the connection is established the phone is directly transferring data with your laptop. No server in between.
I feel really dumb but I can’t find any documentation on his to use it other than instructions on how to install a node