In my native language we have a running joke that goes like this:

    - I had a fie.
    - ???
    - Ah, it's just like selfie, but when someone else is making it for you.

(Originally: jebka/samojebka)

I have heard that as well, but the selfie in those cases was them with whatever they said. So it is more a short form of "took a photo of me with..." which I think is OK.

At a restaurant someone from a group of youngs once handed me her phone and asked me to "take a selfie of us".

This points to a deep rooted problem. Probably OCD.

(Ha, you expected me to write about a problem in how people use language, got ya :-)

Or, a deeply-rooted assumption that "conformance to some arbitrary rules that have been adopted as signifiers of intelligence and class" is in some way an admirable quality, rather than the abilities to infer meaning in the face of ambiguity and to update one's mental model in response to new information (also known as "intelligence")

Maybe, but it’s way more likely that they mean “I took a picture of something with myself in the frame.”

A selfie can really be any picture where you’re holding the camera and in the frame. The subject of the photo can be something other than you.

“I took a selfie with…” means that I and the other thing are the subjects.

“I took a selfie of…” means that the other thing is the subject I’m just in the picture.

No, I very often see people say things like "I took a selfie of my dog" and only the dog is in the picture.

> relying on stock phrases to relay information

You can see this in other common phrases.

Take "miles per hour" for example. I've met plenty of people who can't figure out how long it would take to get from A to B at X mph. They'll deliberate over how they know from running on their treadmill that they run (on average) at 8 mph, and they recall that it usually takes them Y minutes to run Z miles, and then they factor in the diameter of their car's wheels (because surely a car with larger wheels gets there faster for the same mph vs a car with smaller wheels), and finally sprinkle in a bit of multiplication to arrive at their best guestimate.

That is, plenty of people don't realize that "per" means "for each", and that it's not some singular word "milesperhour", but a phrase meaning "miles traveled for every hour spent travelling".

Other fun phrases thrown around without understanding (or with similar words mistakenly swapped in):

Miles per gallon.

For all intensive purposes.

Nip it in the butt.

Bone apple tea.