While advising I am frequently asked about whether a photograph is needed on your LinkedIn profile. While a photograph is recommended, it is personal decision especially if you have concerns with age, a potential employer seeing you, etc.
If a photograph is used, it is recommended to use a clear headshot, from your chest up, dressed in solid professional business attire and using a simple or plain background. Photos taken in casual attire, on vacation, at a party, in a group or with sunglasses on are not recommended.
For additional LinkedIn tips listen to several webinars located in the Virtual Career Center under the "About Us" tab.