Because making shuffling after shuffling is yet another shuffling, that means that there is "closure".
b ɪ k ʌ z WORD_BOUNDARY m eɪ k ɪ ŋ WORD_BOUNDARY ʃ ʌ f l ɪ ŋ WORD_BOUNDARY æ f t ə ɹ WORD_BOUNDARY ʃ ʌ f l ɪ ŋ WORD_BOUNDARY ɪ z WORD_BOUNDARY j ɛ t WORD_BOUNDARY ʌ n ʌ ð ə ɹ WORD_BOUNDARY ʃ ʌ f l ɪ ŋ WORD_BOUNDARY ð æ t WORD_BOUNDARY m iː n z WORD_BOUNDARY ð æ t WORD_BOUNDARY ð ɛ ɹ WORD_BOUNDARY ɪ z WORD_BOUNDARY k l oʊ ʒ ə ɹ WORD_BOUNDARY