Those are REAL sparklers. These are VERY COMMON in the rest of the world. If you go to Greece, every wedding does this… but outdoors. Once in a blue moon you’ll get an indoor use out of them but with high ceilings. Seems in this case it wasn’t properly thought out as there was something above it that was very flammable.
As far as the indoor sparklers go… most, if not all, fire Marshall’s are aware of them. Depending on where you live You’ll have different expectations. New England, not allow to use them unless you have a permit and a pyro license. Of course 99.9% of djs do not have one so you have to use one of the people on the approved registry (it’s like a monopoly over there) and in the end you’re looking at almost $1000 just to get someone to press a button for the first dance.
In NJ, you’re free to use them as you wish. Venues may have their own rules, and one county requires a $75 permit. I’ve used them in many states, most don’t have issues.