The Admissions Committee at the University of Missouri wants to know if you are happy with your admissions interview performance. By asking for self-referential feedback, the admissions interviewers can use your response as a way to measure your ability to self-critique. The way you respond will also speak to your level of self-awareness.
Rather than grade your performance, such as giving a 1-10 response ranking, consider a more conversational response. You could express that you found the experience enjoyable and informative. You could mention that you appreciate the opportunity to share your qualities and interest in the University of Missouri and its veterinary medicine program.
If you approach this question correctly, you'll have the chance to reiterate a couple of stand-out factors about yourself and, simultaneously, overcome any potential objections to your acceptance.