Welcome to your interview.
The question is on your right: Mobile Viewport Optimization. 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.
How would you modify this interface if we needed to optimize it specifically for mobile viewports?