Why should you become this office's receptionist?

Aside from bringing up your skills and past experience, show the recruiter that you've done your research on their company. Explain how the company's values and mission align with yours which is why you believe you're the perfect fit.
"I'm excited to take on new challenges, grow my career, help other people, and be a part of team working towards greater heights. I'll be able to apply what I've learned from the past plus bring new ideas to your organization. It's great that your company values the same principles that I do, I'd love to be a part of achieving your vision for the future."