The congress the title talks about refers to the few talking scenes where people are talking about the current state of the Newt industry. A giant species of newts, that apparently can also talk, is being exploited as labor, as guinea pigs, not sure what else (are they eaten ?).
But most of it are silent (or almost) scenes of newts in the water, or one newt waiting for a lift, or only still shots of the water actually.

The newts that move and talks are like giant marionettes, with metal sticks in them for manipulation and a human operator behind. It is not clear whether this is an artistic choice and we are supposed to ignore it and only see them as the newt creatures, or if it's in universe and the newts are actually manipulated this way.

The final parts of the congress seems to say that [spoiler]mankind is becoming way too dependent on newts, and that they are omnipresent and may revolt[/spoiler].

It seems base on a novel, but does not treat the interesting parts of it. So in 16 minutes nothing happens. We barely know what the newts are, where they come from and they impact on society, nor if the situation could become a war. It's a weird editorial choice and it makes it pretty boring despite the original initial concept.