IIRC the key point there is that it's contextual to whatever generation method scheme you used--or at least what method you told it was used--and it assumes the attacker knows the generation scheme.
So "arugula" will score is very badly in the context of a passphrase of English words, but scores better as a (supposedly) random assortment of lowercase letters, etc.
So "arugula" will score is very badly in the context of a passphrase of English words, but scores better as a (supposedly) random assortment of lowercase letters, etc.