At the time of this writing, the Tobii Partner Window on the back of I-Series devices is only ever used by Tobii’s software and only to show black and white text. The window’s main purpose is to mirror the Message Window in Tobii’s communication programs. That way people can read what is being typed without looking over the user’s shoulder, enabling a more natural face to face communication.

I was curious how hard it would be to control from outside their software and if it could do more. Once I realized it was a full color display, I figured it would be fun to put some of my coworkers in the display.

Turns out Tobii used a graphics chip from FTDI for the partner window:
https://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT81x.pdf
It’s capable of not just color images, but even color video!