578vishnu
Vishnu, they are testing how you think on your feet. And also how good your written communication is.
As long as you are able to write a coherent answer, structure it decently, you should be good. The example shared by them is a light hearted one- if you can add some humor to such a question, it would give the adcom some respite and probably make you more endearing.
Reminds me of ISB's 100 words essay that one had to write just before interviews. They have scrapped it since the past two years, but other programs seem to have introduced something similar to it