Some celebs prefer narcissistic selfies. Some like to post pics of any freebies that come their way in an attempt to keep PR flacks happy, and the gift stream flowing.
Others tend to (cut and) post words of wisdom or spiritual proverbs (not their own, obvs) in a bid to sound caring/sensitive/intelligent/wise, but only manage vacuous and cliched.
And of course, foodie felons - those who cannot go past eating a restaurant meal without photographing it - reveal a deep-seated insecurity to prove they eat out, while the rest of us are having beans on toast at home.
Then there are those who provide a real public service. The ones who show a self-deprecating insight into the person behind the celeb façade. The ones who post interesting images, revealing images, funny images.