From the standpoint of this:

[en.wikipedia.org])

you took two fairly decent waterfall pictures which are cluttered up by trains (i.e. the waterfalls over-predominate the scene at the expense of the train). Don't get all hot an bothered, I've had a lot of people knowlegable in composition critque a lot of my pix mercilessly over the years for precisely the same reasons. Good visual composition is what separates the Steinheimers and Margaret Bourke-Whites from the rest of us. By carefully following composition rules, those described in the link above, I have improved my pix considerably, but in no way can I claim to be a "pro". To make things even more frustrating, some people have an innate knack for composition, like this college friend of mine whose work appears in such publications like Sports Illustrated and Time/Life/Newsweek.