This works by sampling a static scene a very large number of times with a laser flash and a "streak tube" camera that records a picosecond-long movie of the light arriving at a single scanline.

A normal video camera records a frame at a time, this one records a scanline-sized movie at a time. The raw data is noisy but the scene is static so they can sample the same line over many flashes.

After a few minutes of scanning they have a trillion fps video where you can see a wavefront propagate at the speed of light. Amazing.