This is the cover of a book titled More than Half the Sky: Creative Writings by 30 Singaporean Women.
According to the Oxford Advanced Learner’s Dictionary, the word writing in the sense of ‘the activity of writing books, articles, etc.’ is uncountable, hence marked [U], as in the expression creative writing.
By contrast, the plural, i.e. countable ([C]), use denotes ‘a group of pieces of writing, especially by a particular person or on a particular subject’, as in the examples His experiences in India influenced his later writings and the writings of Hegel (Oxford).
Hence, the use of writings in the subtitle of the book is non-standard, because it refers neither to the work of a particular person nor to work on a particular subject.