Well spotted post syncs - I'm surprised they haven't thought of making Ender's Game sooner!;-)Marie
I believe I remember reading that those pyramids are supposed to represent the advanced extraterrestrial intelligence that built the monoliths (in the top pic from the movie 2001: A space Odyssey). If you watch the same part again you'll see the shapes have patterns inside that change and pulsate together and Bowman sees these at some point as he travels through the tunnel in space-time. I understand the point you're making however in that later sci-fi often "borrows" ideas from previous sci-fi - as you have shown above in the comparison with the Ender's Game poster.