This is how we found Ruby this morning. She is a very *special* cat.

Here’s my Ruby saying hi back!

What glorious whiskers!

aww! our kitty does this too, she loves hopping into the kitchen sink for some reason

i think it might be because it has faint food smells, from rinsed dishes and such? maybe

or it's just a box and so she likes to sit in it

She's likely trying to cool herself. Mine does the same in summer, but in the bathroom sink. Picture related:
- perhaps! it's midwinter on my side of the globe though, i don't think she'd be overheating?
  
  she's been sleeping on my laptop for its warmth basically every day

My long hair cat would do this in summer too and even liked it if we gently turned the faucet on. You mentioned it's winter where you live OP so this really is for north of equator where they are facing record breaking heat waves.

Another tip for having cats in hot weather: cold wet washcloths and just groom them with it. In my experience with like... 3 cats even it it is wet enough to wet their fur, they will still tolerate and like it in the heat if you do it in grooming motions. I've also frozen wet washcloths and used them as some sort of bedding option by placing something over it, petting them with it,, or just gently pressing it on some key spots on a cat that would help them feel cool such as below back of ears, spine, forehead, shoulderblades, neck, and especially cheeks/side of face/neck. When they are hot, they appreciate it or tolerate it enough. Know your kitty's body language.

Cats don't really sweat so help yours however you can during this heat wave.

Shit also sorry OP ruby is beautiful and I did enjoy the pic it's just my overwhelming instinct must be to lecture--- I mean share helpful tips with people. :P