Related Clues:

• Brief trailer
• Confusing question
• One in a pic
• Challenging puzzle
• Tough riddle
• Product come-on
• Whodunit, for example
• Little sample
• It's a mystery
• 'Coming up next' ad
• It doesn't have an obvious answer
• Inscrutable sort
• The Sphinx had a famous one
• Puzzle or fashion model
• Difficult question