As an internal recruiter I never judge somebody's skill set and profile by their picture. In saying that when you see many people who use a Snap Chat filtered picture as their LinkedIn profile picture, you do wonder how seriously they are taking the process.
I do feel that the industry that you are in should be reflected in your picture. If you are from a very corporate company and your picture is yourself on holiday relaxing in a deck chair it doesn't set the tone correctly.
As LinkedIn is a professional networking site commercial awareness is demonstrated through your profile, as it is the first thing people shall see of you. So keeping one tone throughout is important.
I personally remember people through their pictures rather than names. That is why I am conscious not to change my picture anytime soon.
Key points to picking your picture, make sure it fits the tone of your industry and the rest of your profile as to be consistent.
Many people invest hours into creating the perfect LinkedIn profile. They tediously list every award they’ve won and scour the thesaurus looking to find the right verb to describe their work experience. Yet, many of those same people spend little time thinking about their profile picture. Maybe it’s a cool candid photo someone took with a smartphone. Or maybe, it’s a professional head shot that was taken in a studio for another job. But either way, people often use what they have on-hand without laboring too much over the impact that photo might have.