They're making another Kai'sa skin and want some ideas for the theme that will sell best before they settle on a design.
Trolly/Memey, Funny/Comedic = Pool Party Kai'sa Villainous, Dark/Edgy, Scary/Horror = Dark Star Kai'sa Cutesy, Feminine, Happy/Cheerful = Sweetheart Kai'sa Fantasy, Anime, Heroic = Super Galaxy Kai'sa Badass, Beautiful, Armored = Void Knight Kai'sa
Probably something like that. They'll probably create some dynamic word-mapping graph with the results and post it up in the boardroom while they do their concept brainstorm meeting with the creative team in charge of making the skin.
It's amazing what sort of psychological data can be gathered from what seems like random words.
Well, league champions are often meant to capture at a glance and "the one word" question actually tells you quite a bit. Kai'sa is a being from the void who survived its horrors and somehow made it out with her sanity in tact. She's also a pretty hot girl who has the big baps. With this question, Riot wants to nail down exactly what people feel when they see Kai'sa.
Is she a scary monster-person from the void? Is she a hot grill in a skintight body suit? Is she a survivalist badass who can fight all sorts of eldritch horrors? Is she a goofball character who is more joke than champion?