We’ve all been in situations where someone hauls out a camera, brings the impending snap to everyone’s attention, calls out “Cheese!” and then presses the button.

When this happened to me a few years ago in China, I thought I’d heard wrong, because the word sounded very similar to cheese. The word they used was “qie zi”, Mandarin for aubergine. What is it with food-related words and social snaps?

It all used to be relatively innocuous. The relatively recent shift from film to digital meant that people were less frugal about how many pics were snapped, and the results could be reviewed (or perhaps even deleted) instantly.

These days, the pics can be on multiple social media in seconds. So far, so good, assuming you’re in agreement that your drunken grin should be all over Facebook or Instagram.

My generation is ‘social media optional’. Large numbers of us are on social media, but many – for a variety of reasons – decided not to sign up. I’m thinking particularly of one couple that shows up quite regularly in my Facebook newsfeed. They aren’t tagged, of course, but there they are, cheerily holding wine glasses aloft as members of a celebratory group.

For the amount of screen time they get, they may as well have their own Facebook accounts.

These are people who chose to not sign up for Facebook accounts. Is it bad form to publish pictures in which non-Facebookers appear, without asking their permission?

Similarly, I have a friend who is on Facebook, but for professional reasons does not post – or appear in – any photos on the site.