This is a fantastic use of rockwork skills, and would look awesome in a swimming pool or fountain. Without being able to see the whole design here I cannot say whether or not these rocks are in a pool or fountain, but it does not really matter. That speaks loudly for the versatility of this design. I personally love waterfalls and rockwork in swimming pools because it makes it feel more like a natural environment. That sort of ambiance goes a long way in a landscape design. For me it is all about a deft combination of functionality and aesthetics.