This is spot-on. Note that the aperture on the camera was quite large, I want to say on the order of 100mm? They sourced really exotic hardware for that cinema camera.

They also had the "Immerge," which was a ~1m diameter, hexagonal array of 2D cameras. They got the 4D data from having a 2D (spatially distributed) array of 2D samples (each camera's views). It's under sampled, because they threw out most of the light, but using 3D as a prior for reconstructing missing rays is generally pretty effective.

But I also understand a lot of what they demoed at first was smoke and mirrors, plus a lot of traditional 3D VFX workflows. Still impressive as hell at the time, it's just that the tech has progressed significantly since ~2018.