I think I've seen this animated (... -> -> . -> .. -> ...), this is quite good. But the animation is important. Without it user can think that the app froze, especially in the world where every other app shows some sort of animation.
Yeah, works only the other way: the fact that the loader is still means one of two things — either the app is completely stuck or it ignores UI conventions of the last decade (which can be good or bad, depending on domain).