just look at the room's configuration and you can immediately tell that the goal was to literally corner Zelenskyy and hammer him until he loses his cool and lashes out. It really impresses as Vance orchestrated the whole thing, but he hasn't thought about that someone fighting putin, a room full of spongy suits might not be scary enough.
I assume they wanted to make Zelensky seem desperate and unhinged. But this backfired, since Zelensky remained calm throughout, but Trump and Vance flipped out when Zelensky pointed out that the distance alone won't protect Americans from the fallout of further Russian aggression. And most EU leaders professed their support for Ukraine after the meeting. So, basically, the shouting was planned, it was just that they planned for Zelensky to do the shouting.