If you look at the the red bull (logo on the airbox spine) then compare the real RB20 running at Silverstone and the public launch car......the image is substantially different between the two.
Unless that cover changed, they are not the same car.
Those two still images appear on page 19 and 20 of this thread for comparison.
Can the public launch be just a "studio" chassis? Just a mock up while the real one that was running simply wasn't presented.