Firstly, I'd just like to say that I am not referring to careers where your physical attributes are key to your success such as acting, modelling etc. Now that that's cleared up, my rant shall commence!
When I see that an individual has included a photo of themselves on their CV when there is, in my opinion, no need, I instantly assume they must be narcissistic. Why else would they include it? Unless they think that their looks for whatever reason will give them an advantage in their application..
In employment, wouldn’t you rather be recognised based on your skills and experience than having someone judge you because of what you look like? After all, we have no control over who is looking at the photo and what their personal bias’ may be. People will always have their own personal prejudices and they can always make assumptions about you based on what you look like.
You could say well why do you have a picture of yourself on LinkedIn then, isn't that your virtual CV? Yes, yes it is but it's still not in the same league as a physical CV. Personally, I do not use my LinkedIn to apply for roles. I have always applied for roles the traditional way with a standard style CV that showcases my past work experience as best as I can. If a recruiter likes the look of my experience based purely on this then proceeds to find me on LinkedIn or social media to find out more about how I may fit for a role they have in mind, they can do so. If they then decide to judge me on my looks, as all humans do, I can still take pride in the fact that they will have gone to the effort because they liked what they read about me as a professional. And even if they then go on to make up their own opinions about me from a picture, at least I'll have already caught their interest with my skill-set. Your skills will always get you further than your looks in the end.
Always entice employers with your skills and experience first rather than their perception of you.
In a nutshell, including a photo is useless because: 1. The hiring managers will google you anyway. 2. The purpose of a resume is to get you an interview. Be noticed by your skills and qualities, not looks.