I used to work for a (school picture) photographer. Despite the fact that he had been earning a living for 25 years as a photographer, it was like he was still repeating his first year, over and over. Just as with winding cable, there are a few right ways to do things, and many, many wrong ways.
The way the camera is being held in the photo (this is, left hand finger-gripping the side of the camera) is guaranteed to deliver camera shake.
The left hand, palm facing up, cups the camera, steadying it - this force the elbow against the body, providing more stability. The fingers do the focus (and f-stop, in the old days.)
Right hand, shutter speed, and other settings, and shutter release.
When you think about it, almost all cameras are left-handed: functions requiring fine motor control and strength are performed by the left hand. The right hand performs mundane, easy functions.
I think there was an episode of Castle where Castle holds a camera correctly. One of the few times...