If you take a look through your LinkedIn connections - how many of them have photos that they took in their car? How many have photos that they have conveniently cropped someone else's head out of? How many of those photos do not represent the professional nature that they're trying to get across?
My guess would be the vast majority of them.
Every now and again I photograph a professional that is looking for a way to make themselves stand out. I get to take photos of these people that will represent their professional experience and attitude. By far, these photographs are my most diverse in terms of age. I've done professional portraits for people at the beginning of their careers all the way to people who have their own businesses and are on top of their game.
A good professional portrait could be the key to landing that job you've been eyeing - Enhance your professional presence online and off.