Welcome to your interview.
The question is on your right: Framework Choice for Ambiguity. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
What project management frameworks (Agile, Scrum, Waterfall) do you find most effective for highly ambiguous technical initiatives at Pinterest, and why?