The fashions and car driven by Barbara indicate the story is happening contemporaneously (around 1946), but the opening daytime shot of Times Square shows vehicles from the early 30s and theater marquees with titles of movies released in 1933. Later in the film, a night-time shot of Times Square shows marquees promoting 1937 movies.
The name on the awning of the hotel in which Hugo is staying does not match the hotel name on his room key tag when he checks out.
At the beginning of the film, when Wells enters his office, a moving shadow of the camera falls over the backs of Bob and Jingles as it follows Wells across the room.
When Jingles and Bob turn away from Jackie to approach the front desk at Bronson's hotel, a moving shadow of the boom microphone falls across Jackie's face and the front of Bob.