masking piece vs scenery

masking piece and scenery both are nouns.

Word	Noun	Adjective	Verb	Adverb
masking piece	Yes	No	No	No
scenery	Yes	No	No	No

As nouns, scenery is a hypernym of masking piece; that is, scenery is a word with a broader meaning than masking piece:

masking piece: scenery used to block the audience's view of parts of the stage that should not be seen
scenery: the painted structures of a stage set that are intended to suggest a particular locale

Other hypernyms of masking piece include scene.

masking piece (noun)	scenery (noun)
scenery used to block the audience's view of parts of the stage that should not be seen	the painted structures of a stage set that are intended to suggest a particular locale
	the appearance of a place