To answer, consider an illustration. A Watchtower Study that is well - conducted is like a bouquet of flowers that delights the eye.
إِلَيْكَ هذَا ٱلْمَثَلَ :‏ يُشْبِهُ دَرْسُ بُرْجُ ٱلْمُرَاقَبَةِ ٱلَّذِي يُدَارُ بِمَهَارَةٍ بَاقَةَ زُهُورٍ مُبْهِجَةً لِلنَّظَرِ .‏