pop out vs appear

pop out and appear both are verbs.

Word	Noun	Adjective	Verb	Adverb
pop out	No	No	Yes	No
appear	No	No	Yes	No

As verbs, appear is a hypernym of pop out; that is, appear is a word with a broader meaning than pop out:

pop out (verb)	appear (verb)
come out suddenly or forcefully	come into sight or view
exit briefly	be issued or published
bulge outward	come into being or existence, or appear on the scene
appear suddenly or unexpectedly; happen unexpectedly	appear as a character on stage or appear in a play, etc.
	give a certain impression of being something or having a certain aspect
	(of a proposition) seem to be true, probable, or apparent
	present oneself formally, as before a (judicial) authority