Sand on a plate gives you a two-dimensional map of the nodal lines. Oobleck — cornflour and water — stiffens under shear, so on a vibrating plate it climbs, forms fingers and briefly holds shapes that sand cannot. The question the video asks is whether that can be steered into anything you would call a cymatic sculpture.
The answer is partly. The results are more chaotic than the still figures a plate gives with powder, because the fluid's response depends on how hard it is being driven moment to moment rather than only on where the nodes are. But it is a genuinely different regime, and worth an afternoon if you have a plate already.
The build is documented as an Instructable linked from the description, and the channel has a companion adjustable Rubens tube project.