Tesla revealed the Cybertruck’s seats in a new video showing off the tail robot, a robot that mimics a person sitting in a seat.

Yes, a robot with a tail... It's actually a Fanuc robot, which effectively simulates sitting on a bench, thousands of times, to test its resistance. 
With the Cybertruck finished, with back-to-back launches promised, here are some more details.  The seats of this pickup are shown in a video shared by Tesla itself.  Indeed, the design is not surprising, it just reveals organic lines that fit perfectly into the image of the car itself. 
Given the Cybertruck's production status, with the first units promised to be ready in August, it's likely that these are already in-production seats as well for pickup assembly. 

The Fanuc robot has been adapted by Tesla to replicate the effect of a lifetime of use of its seat by an average person, performing 50,000 entrances and exits.  This robot has already been announced by the company in 2019 with Model 3 seat tests.
Another video Tesla shared recently that makes any car or cleaning fan nervous, shows someone pouring wine over a white seat in one of Tesla's cars, to show how easy it is to clean, without leaving stains.  The relevant information is that most stains on your seats clean up easily with warm water and a microfiber cloth.