If you use any of the social media platforms, such as Facebook, Twitter, or LinkedIn, your image or photo is everywhere. Anytime you post anything: a blog, a tweet, an ad, or change your status, etc., you are representing yourself, your company and your brand.
I would suggest a businessperson look as recommended by many internet marketeers.
Also consider that websites with photos of uniformed people convert higher numbers of visitors into paying customers.
However, using an image of a cartoon character or realistic fun character is a good marketing strategy (think of Macdonalds).
This website advises Google regarding website conversion strategy resulting in the Google optimizer:
…look at the fact that they are using a cartoon image to promote themselves.
Any blogs, tweets can be added to by other employees under a generic image.
If it is just yourself that is actively involved then a shirt & tie/uniform photo would be the best image to project for a personal approach depending on the type of business.