Live-stream "health warnings"
While cognitive diversity, including getting ideas from strangers, can help deal with complexity, we need to be careful. Unconscious incompetence of individuals can take months or years to overcome; this is dangerous.
This is simply a demonstration of how agility might work. Not all of the people in this demonstration are UX competent. Therefore the group is experimenting with "Mob UX". John made up that expression based on Mob programming, except this is UX.
No silver bullets are offered. None of the methods/frameworks shown might work in your context. This is a demonstration of a thinking approach, an approach for potentially avoiding wasteful investment. Agility is not for everyone. If approaches are mentioned, they might or might not be appropriate in different contexts. Seek advice from your agility coach. Avoid "copy & paste".
This thinking approach is intended to be complementary to whatever is already happening, .e.g, the scientific method. It is for "safe to fail" experiments. For experiments to be safe, we must be able to afford to lose, and no living being should be harmed in any way by undergoing experiments, psychologically or physically. "Safe to fail experiments" are best attained by running multiple tiny experiments in parallel so we can emphasize winning experiments, if any; that way we hope to avoid "change theatre", that is, pretending experiments are successful.