Continuity mistake: As Lois is ranting to Perry White about her report, the door to Perry's office is behind her. You can see the writing of "PERRY WHITE EDITOR" on the door through the glass, backwards as it is on the other side of the door. The edge of the letters of the P in Perry and the E in Editor are about 3 inches from the edge of the window by my best guess. A few shots later, it cuts to outside this door showing Jimmy Olson eavesdropping on the conversation from the other side of the door. Now suddenly the letters are closer to the edge of the window, now being about only an inch. The font style of the text on the window also changes slightly.
Picture added by Quantom X