Here’s a place to collect gifs of the Te – Sassy Head Push signal, which is described thusly: “The head nods with a plateau velocity and an embedded sassy movement pattern, swerving as it nods."
The gifs don’t need to show just this one signal in isolation, necessarily – as long as the relevant signal is clear.
Here’s an example of Emmy Rossum, who hasn’t been officially typed but who I believe to be a Te-lead, doing a sassy head push: