It could have been anything readable. I got the feeling it was either a Kindle or something like that or maybe even a hardcopy of something printed or written on paper. This was just a hunch but I think it's being validated in my mind by the fact that there was no light seeming to shine on the driver's face but that's probably due to the night vision camera not picking up that type of light? I don't really know. My mind is filling in a lot of gaps here, I realize.

EDIT: Upon re-watching the video a third time and really paying attention to this I don't think there is any real way for us to know without confirmation from the driver them self or an official report on the incident. My mind was definitely deciding things that just aren't discover-able from the video itself.

Here we have it, I believe:

"Uber also developed an app, mounted on an iPad in the car’s middle console, for drivers to alert engineers to problems. Drivers could use the app anytime without shifting the car out of autonomous mode. Often, drivers would annotate data at a traffic light or a stop, but many did so while the car was moving"

https://mobile.nytimes.com/2018/03/23/technology/uber-self-d...

The whole project seemed designed for an outcome like this. Eg allowing app to be used whilst on the move, after reducing from 2 to 1 operators. Culpability ought to lie with Uber.

Here's a picture of the Uber car from inside. No FLIR, just GPS:

https://cdn.geekwire.com/wp-content/uploads/2018/02/Front-_-...

A different picture from that article shows that under the GPS is the gear stick, an emergency button, and a cellphone charger.

According to the filename, those are iPads, which implies they could have been displaying anything (not just GPS).