I believe the pivotal point is the man and his reflection. It has action and poses the question of why is he jumping across the water in that location. Also where is he going to? The figure is much darker than the surrounds and the eye is constantly drawn to it when often we are drawn to lighter things in a photograph such as the sun.
I attempted to create a decisive moment catching the ball in mid-flight off a cricket bat. It showed how, shooting on single shot, how difficult was to get all the elements of shadow, action and interest in the frame. Even though the second shot has a nice ball shadow, there is action and shadows the image still does not work that well because of the distractions in the background.
Cartier- Bresson on the other hand has managed to capture not only the action of someone jumping across the water but to do within the frame as a whole. The railings of the station frame the image with the vertical parallels. The ladder like structure in the water runs across giving us a sense of direction.
In the background we can get a sense of it being an urban area, but no specifics. There is the sign telling us it is a railway station then next to it is a poster of which the subjects in it also seem to be jumping in a similar vain to the main subject.
Overall the image as well as framing the photo well gives us a good context but without leaving us to fully comprehend what the subject is doing.
www.100photos.time.com (Accessed July 17)