This waterfall picture is a combination of two different pictures. One was taken with a short shutter speed, so that the water appears frozen. The other was taken with a long shutter speed, so that the water appears as a silky flow. There are people who prefer both; there is no “right” way to photograph a waterfall because each of the two techniques illustrates something different.
(You can see the two original pictures below; click on the pictures to see larger versions.)