This is interesting in terms of the ubiquity of LinkedIn - the lack of a photo on a CV is obviously to do with reducing bias. For example, if a recruiter doesn't know how attractive someone is, that won't influence their decision, and rightly so. But now that everyone's on LinkedIn it's easy to track down someone's photo if you want to. I often do this with clients who approach us through email because I like to have a face in mind when I speak to them on the phone, but it's easy for recruiters to misuse.