This question How do electric field wall dehumidifiers work?
was closed with the explanation "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design."
I understand that the reasons for closing a question don't always match the options provided, and perhaps the people who voted to close had something different in mind, but the question is right there in the title: how does this device work, not "how do you use this device", and it's difficult to believe that the people who voted to close missed that.
So maybe some people think that questions about mechanisms are not about design, in which case questions like this one are off topic: Explain what is a transistor in plain English!
... or maybe questions about how devices works are OK if the device is a transistor, but not if the device is a truck. But that wouldn't explain closing a question about electro-osmotic effect.
... or maybe questions about devices that don't work are off topic? If so, I thinks that is a bad criteria. Lots of electrical/electronic designs don't work: understanding how and why things don't work is an important part of the electrical/electronic design process.
What's it to be? Was the question on topic, or if not, can we get some clarity on what exactly was off topic about it?