prose vs expressive style

prose and expressive style both are nouns.

Word	Noun	Adjective	Verb	Adverb
prose	Yes	No	No	No
expressive style	Yes	No	No	No

As nouns, expressive style is a hypernym of prose; that is, expressive style is a word with a broader meaning than prose:

prose: matter of fact, commonplace, or dull expression
expressive style: a way of expressing something (in language or art or music etc.) that is characteristic of a particular person or group of people or period

Other hypernyms of prose include style.

prose (noun)	expressive style (noun)
ordinary writing as distinguished from verse	a way of expressing something (in language or art or music etc.) that is characteristic of a particular person or group of people or period
matter of fact, commonplace, or dull expression