He paused as a rapt expression widened out from his daughter's nostrils, forcing her eyebrows up and her lower lip down in a wide noiseless grin, an expression in which Jack was startled to recognise his wife feigning pleasure at cocktail parties. "And all of a sudden," he whispered, "the whole inside of the wizard's house was full of the smell of – roses! 'Roses!' Roger Fish cried. And the wizard

these lines refer to the scene after d spell was cast on roger skunk.
he said he wanted to smell lyk roses so the wizard granted his wish..and soon after he completed reciting the magic spell roger skunk's foul odour disappeared and he smelled of roses and as a result the whole of the wizard's house smelled of it too.
after his work was done, the wizard demanded 7 pennies as his payment.

hope it helps :)