poetry vs expressive style

poetry and expressive style both are nouns.

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

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

poetry: any communication resembling poetry in beauty or the evocation of feeling
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 poetry include style.

poetry (noun)	expressive style (noun)
literature in metrical form	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
any communication resembling poetry in beauty or the evocation of feeling