I think this is saying he can see who is connected to his machine and not the site visited. The image looks like a netstat or tcpview output.
I can see this if I use the debugging option in Firefox.
It looks something like this:
a=candidate:2218299339 1 udp 1694498815 x.xx.xx.xx 47226 typ srflx raddr 0.0.0.0 rport 47226 where x.xx.xx.xx is the IP address
It’s all encrypted UDP packets.
See this thread where we discuss this A follow up question about Snowflake