I believe "fluffality" is a combination of "fluff" and the compound suffix "-ality"
"-ality" is a combination of the suffix "-al" which means "of the kind of, pertaining to, having the form or character of", and "-ity" which means "having the quality of"
So "fluffality" would, in a sense, mean " the quality of pertaining to fluff[iness]"
It's not a formal word, but in English it's okay to create words likes this as long as the normal conventions are followed.
That being said, perhaps "fluffability" would have been more easily understood.