basically *spoilers up to now Wanda was left deeply disturbed after Thanos killed Vision, and after the Avengers beat Thanos in Endgame, somewhere down the line, she retrieves Vision's body from a secret government facility.
she then uses her powers to take over a town to create an idyllic environment where she revives Vision, but he picks up that there's something wrong.
there are also government forces outside of the town monitoring what's going on inside, and what they see is the sitcom stuff going on inside. at this point, Wanda knows what's going on after she forcibly removed one of the agents, and warns the others to leave her alone.
It's also implied its not all her. Pietro showing up wasn't her. She also might not have started it, nut is taking advantage of it.