Paste Magazine has posted an article where Axel Torvenius, the art director of the game at MachineGames, describes several concept art of some environment of the game, like this one:
In this game we have a surreal mix. The classic American dream of blue sky and diners, classic American cars and girls walking down the street smiling. But there is something off with this environment. Nazi jetfighters are roaring in the sky overhead, a Nazi parade in the distance and those girls are walking down the street hand in hand with German Officers. Designing a fictional America run by the Nazis has given us some very surreal moments in this game.
Many other concept art will be also detailed in the upcoming book “The Art of Wolfenstein II“, released on November 7.
Here are some other concept art of the game: