poser vs artist's model

poser and artist's model both are nouns.

Word	Noun	Adjective	Verb	Adverb
poser	Yes	No	No	No
artist's model	Yes	No	No	No

As nouns, artist's model is a hyponym of poser; that is, artist's model is a word with a more specific, narrower meaning than poser:

Other hyponyms of poser include sitter, dressmaker's model, photographer's model.

poser (noun)	artist's model (noun)
a particularly difficult or baffling question or problem	a person who poses for a painter or sculptor
a person who poses for a photographer or painter or sculptor
a person who habitually pretends to be something he is not