The word "门口" is formed through the direct, logical combination of two pictographic characters. The first character, "门", pictorially represents a door or gate. The second character, "口", literally depicts an opening or mouth. When placed together, "口" functionally specifies the location of the opening associated with "门", thus creating the composite meaning of "doorway" or "gateway", referring specifically to the entrance space itself rather than just the physical door.