While parked but with the car on, open the door and turn the steering wheel all the way. You should be able to see the rear wheels turning (up to +/- 5 degrees). It reduces turn radius by about 10% so not huge, but something.
My understanding, from briefly talking with a dealer, is that this isn't merely a software update; it's a hardware update too, which is why the dealers are waiting on parts.
Thanks Wawando, but I'm more curious about what it looks like on a US-market car, because my understanding is Tesla patented the features so nobody else can have such a display here. Which is why I was surprised OP reported his US-spec car having it working.
I'm surprised that you say the display showed surrounding traffic because I asked a salesman about it and he thought all features of that screen were disabled for the US market. And certainly on my current car (GV60) every feature is disabled.
Can you have a passenger take a cellphone video of...