Possible Clues:

• Difficult to analyse; understated
• Understated - discreetly clever
• Slight and difficult to detect, like some humour
• Understated; devious
• Fine, delicate or elusive
• Delicate, hardly noticeable
• Delicate or indirect
• Delicate - crafty - indirect
• Slight and difficult to analyse amid bustle
• Very nice translation perhaps lacking appeal