What is wrong
The water level is so low that you can see the pond liner.
The fountain nozzle height is not much above the water but lower than
the pond edge, so if the pond was filled more the nozzle would be under
water.
The rock edging is not aligned, there are too many gaps between the
rocks and the rocks do not "align" with each other
The rocks also look like they have just been placed around the edge.
If you look at the waterfall you will also see there is the water
supply pipe, it is not hidden.
The water fall is feeble.
The corrections
With a little effort this could be a very nice pond
The rocks could be better positioned, and sunk slightly into the
ground, more rocks of differing sizes would also look more natural, as
opposed to all the rocks being the same size
The pond needs more water to hide the liner
The fountain nozzle could easily be raised (or the pump stood on a
brick) to be above the new water level
The waterfall supply pipe could also be hidden, by burying it under the
rocks or bring it up under the fall of the water fall.
The waterfall is feeble because it is the same pump that is running the
fountain, although you can do this you do need a powerful pump to do it.
Also if the waterfall was to protrude further into the pool there would be
more of a fall.
You may be wondering why i have not commented about the soil
border, the area between the rocks and grass, this is because this is a
"grey area" ideally it should be covered with a weed proof membrane and
then covered in gravel, this would serve two purposes. One would be a
gradual change from gravel to
rocks, the other is having a pond edged by grass is a pain when you cut
the grass, as often the cuttings end up in the pond.
To save embarrassment we have not published the owners name.
see here