Here is a link that provides some insight:
Snapshot vs Good Photograph: 7 photographers weigh in
In most cases a snapshot is literally that. A snapshot of a moment in time. Sometimes it works well, mostly its simply a moment in time.
The image when posed, or framed, mood lighting, angle, framing, use of various rules like rules of thirds, golden circle, etc that comes into play.
In the example in the link, there is a woman who is with her kids in a stroller. if the image had better contrast and different angle, along with some amount of framed "drama" or such the image would pop out.
many pro end photographers will tell you that about 60%+ of their own shots get dumped because they simply don't capture the intent.
In this link the author explains how to pose the camera to get the "better" photo.
Let’s Talk: Portraits vs Snapshots
in most instances, simply changing the position of the camera and angle of light does the trick.
Other times its simply the right moment at the right time, vs having a staged photo.