subtweeting vs human activity

subtweeting and human activity both are nouns.

Word	Noun	Adjective	Verb	Adverb
subtweeting	Yes	No	No	No
human activity	Yes	No	No	No

As nouns, human activity is a hypernym of subtweeting; that is, human activity is a word with a broader meaning than subtweeting:

subtweeting: the act of tweeting without tagging a user so that they will not see the post
human activity: something that people do or cause to happen

Other hypernyms of subtweeting include act, deed, human action.

subtweeting (noun)	human activity (noun)
the act of tweeting without tagging a user so that they will not see the post	something that people do or cause to happen