photo op vs occasion

photo op and occasion both are nouns.

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

As nouns, occasion is a hypernym of photo op; that is, 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
occasion: a formal or official social gathering or ceremony of people

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

photo op (noun)	occasion (noun)
an occasion that lends itself to (or is deliberately arranged for) taking photographs that provide favorable publicity for those who are photographed	an event that occurs at a critical time
	a formal or official social gathering or ceremony of people
	a rational motive for a belief or action
	an opportunity to do something
	the time of a particular event

photo op (verb)	occasion (verb)
	give occasion to