I don't think people in the UK always do. I do here because I have to. On Twitter, Facebook and Instagram, I just use a nice picture of a random thing. I had a quick look at my Facebook friends and Instagram followers, and I'd say only about half of the avatars are a picture of the person. The rest are pets, flowers, cartoon characters ...

Hey Charming, it's a good question as I had the same one - why in China lots of my students are using pets as avatar pictures on their wechat accounts, for example? Why not real face?

Hi Charming, we like to use real photos as we can see what the person is like. There's an expression: "A picture says 1000 words."