The game helmet and the star flickering.
Were the sophons already deployed? How did they make the stars flicker?
It wasn't made very clear what was up with that ...
And the helmet ... in order to work with the human brain there should had been massive amount of information about the human anatomy sent to the San Ti to create it ...
Yes, it's from the book though the person in the book (Wang) didn't use the game helmet and instead was tasked to go to a special research facility that measured the background radiation of the Universe at a certain time and use their scientific headset to view the Universe 'flickering'.
It is explained later that the pair of Sophons (who had been deployed and already arrived at Earth to halt all science from that point on) did this by unfurling to a shape large enough to cover the visible Universe from the Earth so that they could give the fake flickering demonstration.
Sophons, basically put, are created from unfolded photons and are a type of computer which can reside in other dimensions.
Hope that answers your questions.