Here’s a place to collect gifs of the Ni – Intense Scowl signal, which is described thusly: “The scowl contracts from the outer tips of the eyebrows to the center of the eyes, causing an intense clash between frontalis and obicularis muscles."
The gifs don’t need to show just this one signal in isolation, necessarily – as long as the relevant signal is clear.
Here’s Jodie Foster doing what I think is an Ni Intense Scowl, but she's not in the database. Let me know if you disagree 🙂