From the video, it appears that they are dipping by 1cm, measuring volume, dipping by 1cm more, measuring volume, etc. So they end up, effectively, with a set of 1cm slices and the volume of each slice. For one orientation. Then they repeat, getting slices at a different orientation.
Not only would it not work with something absorbent, but (per other comments below) does not (currently) work with shapes that trap air or catch liquid.
I think they're 3D-printing test shapes because it's the simplest way to generate interesting test structures. Otherwise they'd have to manufacture (for example) a bunch of columns plus a ball using metalwork or wood or something. Some of their models look like they were originally scanned from small sculptures -- although in this day and age, it's possible they were just created as 3D models in the first place.
Not only would it not work with something absorbent, but (per other comments below) does not (currently) work with shapes that trap air or catch liquid.
I think they're 3D-printing test shapes because it's the simplest way to generate interesting test structures. Otherwise they'd have to manufacture (for example) a bunch of columns plus a ball using metalwork or wood or something. Some of their models look like they were originally scanned from small sculptures -- although in this day and age, it's possible they were just created as 3D models in the first place.