The "triggers" seem to be the difference. The video shows it tailing strace, and only waking up the display and dumping data when it sees the poll() system call in the strace output.

Then they show a fancier example of a specific pattern of recvmsg(11,...) happening a specific amount of lines below poll(). That ends up showing the flow of data to a specific socket.

Or without triggers, it only shows you the latest when you tap the space bar or some other key.