short subject vs pic

short subject and pic both are nouns.

Word	Noun	Adjective	Verb	Adverb
short subject	Yes	No	No	No
pic	Yes	No	No	No

As nouns, pic is a hypernym of short subject; that is, pic is a word with a broader meaning than short subject:

short subject: a brief film; often shown prior to showing the feature
pic: a form of entertainment that enacts a story by sound and a sequence of images giving the illusion of continuous movement

short subject (noun)	pic (noun)
a brief film; often shown prior to showing the feature	a representation of a person or scene in the form of a print or transparent slide or in digital format
	a form of entertainment that enacts a story by sound and a sequence of images giving the illusion of continuous movement