I can't say I have experience earning a merit based scholarship at this point, but I do think the adcom had to like you enough to give you an II, acceptance, and now a nomination for a scholarship. Presumably they know you will be a good fit at the school and that you will be successful, but good on you for wanting to prepare for that anyway. I think the vision shifts, however, from "why us?" to "do you think a scholarship will help you/how do you think it will?"
When I applied for scholarships after my acceptance this cycle for the new med students, the prompts I had were:
- describe your professional goals and how a scholarship would help you meet them.
- please describe talents/skills/etc that you can use to advance our mission (probably something you already had to answer in your secondary and interview)
- are there any other attributes you'd like to share regarding your application? (also probably not something new to you. It's different when you're applying for the scholarships as oppose to the school coming to you instead with a nomination - they love the attributes you have enough to extend it to you but it's always worth practicing to reiterate it in the interview)