Why does superuser display "1 question with new activity" , why not simply 1 new question.
Because there are other tabs which show questions not in the order in which they have been created, but based on their “activity”. An activity could be:
- a totally new question
- revisions made
- bounties placed
- reopened questions
- “bumped questions” (the system automatically bumps older, unanswered questions to the front page, to give them some exposure)
Strictly speaking, of course, the the “with new activity” string could be left out from the Newest view.
The wording might be questionable though it isn't objectionable.
It is, as slhck says, to reflect any activity, not just new questions.
The other purpose, though, is that clicking that bar doesn't re-fetch the entire window contents, only the new data.
This does mean it often will fetch a spam post that has since been cleared - sometimes they last only a few seconds before being expunged - but it is a bit of a data saving to only fetch the new headers rather than the entire page.