people complaining about Issa Rae's acting in Hotel Reverie simply don't understand the entire point of that episode
first of all, she is simply thrown into the simulation without any prior warning, how would YOU react if you're suddenly walking into a black and white world from one minute to the next and everyone is dressed in 1940s outfits and also you're the only one who's an actual person and not just an AI? It's perfectly normal behaviour to be stunned and confused
also Dorothy is probably one of Brandy's favourite actresses from back then, seeing how she loves old movies, she might even be a role model, with Brandy being an actress herself...how would you react if you suddenly saw your celebrity role model/crush/one of your favourite actors?? And not only SAW them but getting to interact with them, actually being in a movie with them...of course this is stunning and exciting, actual irl actors being interviewed about their more popular co-stars always end up gushing about them, being star-struck, even despite being stars themselves, so it's a normal reaction, especially consisering that Brandy didn't have ANY time to adapt to the situation
and then later on, after Brandy gets stuck in the simulation (either for, as shown by the calendar approx. "only" 2 months, or more likely, actually, if Jack's assessment was correct and every second passing in real time is 6-7h inside the simulation, it would be 2 years (!!!)) and her and Dorothy are falling in love for real, just to have that taken away with the snap of a finger once the system restarts, and be thrown back to the very beginning, when they basically just met?! Of course she would be utterly shaken and heartbroken, unable to function and act her role, she's a person who just lost the love she shared for 2 entire years... only to then actually lose Dorothy about half an hour later when Clara gets shot...
Brandy's reactions to everything that's happening is deeply human, and therefore amazing acting, because it's EXACTLY what you'd expect someone to react like in a situation like that, and it adds to making this episode even more heartbreaking than it already is
