A brief internet search says the signal in the real thing is mechanically generated by pressing the trigger on the hand unit, helpfully called the M57 firing device. So just shorting the wires without external power wouldn't trigger it.
That activates a blasting cap which is installed in the mine when it's placed. I'm pretty sure it just needs one cap to work, but there are two places for them on top - the little upside down tophats where the wires end in the picture. So the one in the image might be wired wrong; both wires would need to go to the same cap on one side.
I don't know if a doorbell has enough juice to activate a blasting cap.