~snip~
Even if you see something like that, it doesn't mean it's actually real.
The streamer could easily just login there with another username, and send money to himself, or a friend, etc, to create the idea that it's working.
It's pretty common actually to see things like that when they want your money. It makes it more attractive for a lot of people to take the bait.
We certainly don't know how the streamer plays gambling. Either he uses his own account or uses someone else's account or even the casino provides an account for him so he can stream his gambling games. We only know based on what we see and what they do. And that was enough for them to entice people to join and even use their referral link. And those of us who watch it shouldn't easily follow what they say, and if we want to join a casino, it's best to find a trusted casino and don't follow the streamer if you don't know him well.