I think a lot of fields of engineering have analogous questions actually. EEs ask to explain a circuit or draw a new one. Mech Es ask to design some piece of simple hardware with a clever catch. Interviewing is just hard, it’s impossible to cover breadth of knowledge in 45 mins so we end up with little brain teasers.

This particular question is a bit ill formed and confusing I will say. But that might serve as a nice signal to the candidate that they should work elsewhere, so not all is lost.