photo op vs social occasion

photo op and social occasion both are nouns.

Word	Noun	Adjective	Verb	Adverb
photo op	Yes	No	No	No
social occasion	Yes	No	No	No

As nouns, social occasion is a hypernym of photo op; that is, social occasion is a word with a broader meaning than photo op:

photo op: an occasion that lends itself to (or is deliberately arranged for) taking photographs that provide favorable publicity for those who are photographed
social occasion: a formal or official social gathering or ceremony of people

Other hypernyms of photo op include affair, function, occasion, social affair, social function, social gathering.

photo op (noun)	social occasion (noun)
an occasion that lends itself to (or is deliberately arranged for) taking photographs that provide favorable publicity for those who are photographed	a formal or official social gathering or ceremony of people