Last week I read a book that had me thinking about how annoying it is when the author leaves out information that's clearly know by the viewpoint character. I.e.: Oh, her, CharX thought. It's she that's been causing all this trouble.
Who is she? Obviously CharX knows who she is, but the reader doesn't know anything more than that it's not a character who would have been described with some other pronoun.
I was all ready to theorize that I don't like this because I read so much, and I'm just tired of not knowing things but I don't actually care enough to be motivated to want to know more. I was all ready to call it fake tension, and a bad thing, because obviously the construction, in addition to whatever (fake) tension comes from not knowing, is also promising that with a little bit of patience, all will be revealed. Because it doesn't make me eagerly read on because I must find out, it just makes me roll my eyes and keep going because I will find out.
But I did wonder if my reaction was because I've seen this technique so much before, and if a less jaded reader would feel it as real tension, not fake tension...
I'm still wondering about that part, but this week I read a book that I think did a better job with the same thing, and fake tension or not, I'm not as willing to classify it as a bad thing.
In this particular scene, some details were left out and kept for later, but I think they were details that would have taken away from the scene (which was an important scene). The scene had to be there, but the details didn't, and might have gotten in the way.
(Possibly the distinction is that tension wasn't really the point -- at least, that's how I read it.)
So I guess...it all depends on how you do it. As with most things.