I really get this weird sense from Kat like she was raised by the YouTube Trending feed or something. She's like a blank person who just tries out things that are popular and when it passes time that means she enjoyed it. Her answers sounded like a serial killer trying to blend in, but really she's just that bland and simple.
What's your favorite meme? Uhhh. . .uhh. . .Doge (Is incapable of understanding the Penne meme. It means whatever you think it does, including the literal meaning, and are all disparaging to Phil. . .and he said it. That's it)
What's your favorite band? . . .I really like K-pop. . .BTS is my favorite (Doesn't know any of the group members names, doesn't have a favorite member, can't name any of their songs, doesn't actually know anything about them)
What's your favorite Anime? . . .Oh! Attack on Titan (Pretends she loves all the characters but really can't remember a single one's name, hasn't seen Season 2, isn't reading the manga, sounds like she hasn't watched it in a couple years)
Do you collect anything? No, I don't collect anything. I was thinking about collecting swords, but haven't started. I'm kind of a nerd. (She's talking about Fantasy wall-display steel art. She's not interested in swords, just cool looking flashy things)
What's your favorite horror movie?. . .well, I don't. . .it's not that I don't like them. I get scared so I don't watch them. I do like them, it just has to be the right one. . .for me to watch (Doesn't name any film. Won't just say she doesn't like them)
What's your favorite movie of all time then? Oh! John Wick (This girl really is a pod-person, or she has a medical condition where all her memories reset every 4 years)
What's your favorite place you've been to in the Seattle area so far? Hunh? I don't get it. Do you mean like. . .
To sum up as much as I was able to stand: If she is aware there are people who think something is cool she likes it, even if she doesn't like it. Her favorite things are basically whatever is most popular, but she's not actually interested in them. She seems to avoid (or not be capable of) strong feelings altogether. She seems to avoid having an opinion or anything that would make you think. She likes things that are bright, shiny, flashy, and don't require a mental investment to enjoy. If she isn't mirroring Phil as part of some evil plan then she is the most bland, boring, blank human I have ever seen.
TL;DR Worst character in the DSP Extended Cinematic Universe so far. The writers better have the most autistic plot curves in store for this sub-plot or it's going down as the 'Elektra' of this Cinematic Universe, and considering the pigcult has already made Jennifer Garner comparisons I don't have high hopes.