You can bet they only demo things if they are 100% sure it will work (in a very controlled environment not unlike North Korean "tours"), and even then often it will fail because of Soviet-style bureaucratic incompetence.
I also demo only things, I am sure 100% it will work. Otherwise it doesn’t make sense. Every YouTube technical demo is repeated hundred times until perfect video is made to make an impression, it works 100%. That’s the purpose of demoing something. About bureaucratic incompetence I have no opinion.
You're arguing semantics when the point is that they likely aren't ask sophisticated as they make themselves look.
I heard rumors, that Russian KBG had always eyes on all high levels foreigners in the country. All of them were observed expecting to find something interesting: https://en.m.wikipedia.org/wiki/Kompromat Why should China do it differently? BBC journalist is highly valued target for sure. And there you get bonus points for using this information to showcase facial recognition system in 7 minutes.
First of all it is KGB, and secondly Kompromat is just russian word for blackmail, and I am pretty sure nowadays FSB and any other self-respecting agencies in other countries always keep and eye on influential, wealthy or otherwise having political impact people in their country, that is just national security basics really.