Technical Details section of help explains "we buffer batches of coin flips in advance to ensure a responsive experience. Your coin flips are always drawn directly from a quantum circuit, though no necessarily in real-time."
Thanks for your comment.
Well inspirational stuff is rarely new. There are lots of "best of" topics containing stuff from past. This particular page was chosen on purpose because it is the most interesting of the set. Of course you are free to browse the rest of the set.