"I knew Spike Jonze would do something really interesting with it"

In this quote, Tilda Swinton is expressing her self-confidence and enjoyment in Spike Jonze's capability to develop something special and fascinating. She likely has a strong understanding of Jonze's innovative design and trusts that he will bring a fresh and innovative point of view to whatever job they are working on together. Swinton's use of the word "it" recommends that they have currently discussed or collaborated on a particular concept or idea, and she is excitedly anticipating seeing how Jonze will bring it to life. In general, this quote shows Swinton's adoration and regard for Jonze's skill and her anticipation for the result of their collaboration.