This is almost the same open-ended interview questions I've used for many years, works a charm because it filters the engineers from the chaff (who just copy-pastes code from the internet w/o understanding why)
This is usually one of the three questions I require as part of an application.
The other two are a technical question tailored for the position and the third a 'throwaway' that the applicant answer as they see fit. In the past it's been things like "What is the airspeed of an unladen swallow? (European or African)"
What are you expecting to get from something like that?
In any case, it's a chance to show themselves as a person.