Current use of term "low key"?

[dudsville]

I keep coming across this on line and I don't know how to understand it. Can anyone help? Example I just read from a joke " ... and she low key hates...". Does this mean she calmly hates????

Something like that, I guess. It does seem a clunky way to put things.

I'd take it to mean she hates the thing, but keeps her hatred private nearly all the time (perhaps a few people have been quietly told)

Hates it but isn’t vocal about it due to it not being a popular opinion - I’d say.
She low key hates

Ah that might make sense. I didn't want to post the actual line because the thing she hated, in this meme, was something I didn't feel comfortable posting.

It's annoying. See also use of "legit". "I legit thought I was going to shit myself", for example. Argh!

These things don't annoy me personally, but when Google can't advise me, and there are no children around to ask, I get stuck!

I'm interested in how language is used over time. For instance, I woke up this morning and when I looked out of the window I could hear my long dead grandmother saying "nary a cloud in the sky". Funny to imagine "nary" at some point being a new fangled term that the older generation had to get to grips with!