In near field zone (low frequences, mains and DC-DC converters) the device acts like a secondary coil of a transformer, so it drains power from some other devic

In near field zone (low frequences, mains and DC-DC converters) the device acts like a secondary coil of a transformer, so it drains power from some other device. In far field zone (high frequences, bluetooth, wifi) it captures part of already emmited wave, so it doesn't place additional load on emitter directly. But since device blocks wave propagation through itself if placed between transmitter and receiver it will degrade reception. And that in turn can result in automatic increase of transmitter power (in case of GSM phones at least). Which will increase transmitter consumption.