Possible Clues:

• Business that has projected results
• Key people in charge of returning pictures
• Eventually what happens in start of 12 across ends up here for the viewing audience
• Its patrons are usually kept in the dark
• Theater, the last word in comfort originally, heading west
• Mine engineer in California is looking to show 19 down to an audience
• CIA men vandalised picture-house
• Pictures of guys returning, arrested by US agents
• "Field of Dreams" field?
• The field of film