middle distance vs aspect

middle distance and aspect both are nouns.

Word	Noun	Adjective	Verb	Adverb
middle distance	Yes	No	No	No
aspect	Yes	No	No	No

As nouns, aspect is a hypernym of middle distance; that is, aspect is a word with a broader meaning than middle distance:

middle distance: the part of a scene between the foreground and the background
aspect: the visual percept of a region

Other hypernyms of middle distance include panorama, prospect, scene, view, vista.

middle distance (noun)	aspect (noun)
the part of a scene between the foreground and the background	the feelings expressed on a person's face
	a characteristic to be considered
	a distinct feature or element in a problem
	the visual percept of a region
	the beginning or duration or completion or repetition of the action of a verb