Standard operating procedure for bad guys is to subject captured good guys to something awful. Actual torture can be glossed over if you prefer not to dwell on it. Or you can make it silly, like that life-sucking gadget in The Princess Bride.
Or make it something nominally awful that people have to deal with in real life, like waiting in a queue, or doing tax returns. Imagine a villain who tortures captured adversaries by making them wait in a queue before they subject them to the usual berating and monologuing. Hey, they've got a lot of enemies! What, you expect to be berated as soon as you arrive? Wait your turn!
Commentary by memnarch (who has not seen the movie)
Oh yes, Snoke totally needs to unwind. No hidden agendas with getting that book back, nope. No wonder orangutans make the best librarians. No human fixations or fallibilities to get in the way, easier to maneuver around the library, only need to worry about the books themselves, and unwinding just takes a banana or two or possibly a handful of peanuts.
Rey getting hair poked in one of her eyes along with the extreme contortion is certainly a directing choice. Rey's obviously in a lot of pain, true, but that's more likely to be the twisting than the eye poking. Evil black veins bulging around both eyes would have seemed more in line with the Dark Side; not messing with hair. Do we really need to have Snoke be petty and weird like this?
The Kylo face panel feels meaningful. Like the evil BB droid, just with less panels. Is Kylo going to jump in the middle of this soon? Time for a Kylo vs Snoke fight perhaps? Or maybe there'll be some gestures and Rey will end up strapped to a table again to be taken away. I could see Kylo-Sally trying for a "good cop, bad cop" scenario to get the info as it'd be lost if Rey dies, and Kylo would need to find a different apprentice before taking over as a hidden agenda. And of course, Snoke would argue against that because of what happened the previous time Rey was strapped to a table, possibly pointing out that Kylo nearly died then as well. Though I guess this would be more of a "bad cop, super evil cop" situation as neither of them are exactly good.
Transcript
Rey: You want the list of Force-sensitive families so you can recruit them to your evil cause?
Snoke: The contents are immaterial. The item is overdue. The fines are...
Snoke: Considerable.
Rey: Right. The First Order is a business. But... this is trivial next to a Galactic shopping network.
Rey: What are you up to?
Snoke: You will tell me where the List is.
Rey: There’s more to life than books, you know.
Snoke: But not much more.
Snoke: Order. Tranquillity. And that will do.
{Kylo Ren watches as Snoke applies Force torture to Rey, who is suspended in mid-air}
Rey: {screaming in agony} Where does the Force torture fit in, then?
Snoke: It helps me to unwind.