There are two fundamentally different approaches to giving a demo: Show a lot of cool stuff, or tell a great story.
It’s not that one of these approaches is “correct”. It’s more that they are complementary ingredients that need to be balanced.
A demo that just throws one feature after another at you can be impressive, but it can also grow numbing. It’s hard to remember what you’ve seen, or to make sense of it.
Ideally you want people to walk away with an overarching message. That’s where the story comes in. My current belief is that it is better to show fewer things, and leave people with a very clear understanding of what they have just seen.
And perhaps even more important: A very clear understanding of why they have seen it.