It's actually both

The first is the judgement and planning phase.
The second is when demonic behavior might leak out.

I have to ruin the joke but this is not really accurate.

Cat's are not thinking about "killing" when they have this look. It's the "play & snack mode" a very positive feeling for the cat. They don't have the idea that they might hurt or kill another living being in the process.

The real "kill mode" is when having a dispute with other cats (or cat like animals) that they identity not as a snack but as a cat like thing. And this look is much closer to the left picture.

Learned that in elementary school

The cat will open its pupils when gunting, since closed eyes hinder its sight

In the first photo it looks like it just smoked a joint.

In the second photo it looks like it just snorted five lines and is ready to go scarface.

So yeah, it tracks.

Way back I gave one of my cats one of those toys that's basically a torus with a ball that rolls around the inside with openings on top to allow the cat to hit the ball around. The openings were just a hint too small for the ball to come out without any force. Anyway, I gave my girl this toy and I swear she spent over half an hour just knocking that ball around. I walked up and pulled the ball out and showed it to her and in an instant her eyes went from slits to fully dilated. She didn't attack me though, she just yelled at me instead.

I recently learned that when Ted Bundy got into that violent mood, his pupils would dilate as wide as they could go. His cousin said his eyes went dark.

It's not "kill mode", it's attentive.

There is a whole horror short story in those 2 faces if you are a creature that is smaller than them.

"yawn, that little creature is so boring an unimpressive....I should go break its leg and bite it to see if that makes it do anything interesting."

Offense or defense, both come with claws.

Nothing strange about it.