This sort of information-delivery/propaganda-by-play-acting is so strange to me. Does any Russian watching this actually think this is a live briefing rather than a staged performance?
And if they don't, what advantage does it have over a speech or announcement?

Seems like doing these stages performances on the balance would be an awful waste of time for senior leadership who, at least in theory, ought to be really quite busy and stressed right now.
Just make an announcement, give an address!

And of course I'm not unaware of ritualism in war - most cultures have war rituals. But at least the fetiales throwing a spear at something or purifying the army with a ritual sacrifice (the lustrum) has some impressive pageantry to it.
This is just a mix of boring and pathetic.

...huh, now that I think of it, "war and battle rituals" would make a pretty good blog topic.
Going to add that to the list.