When Chepa talks to Lupe's ghost on top of the clock tower, a building in the background appears mirrored in one of the shots.
At minute 00:30:21, after the accident, an extra, who only should follow with his gaze the transfer of the stretcher with the injured body of the actress to the ambulance, but he looks straight ahead at the "ghost" of the injured actress who was standing in front of him, whom supposedly only "Chema" could see her.