Not management speak; a real military tactic, originally.
In the past, it was a deeply ingrained custom to salute a flag as a sign of respect and patriotism. Many people took flags very seriously, and saluting the flag was a way of saying "I love my country, and the values for which it stands".
Once a conquering army took over, they put up the flag of the invading country instead, and forced people to salute the flag of their new "homeland". Any signs of loyalty towards the old ways were harshly punished.
However, to flush out rebels, sometimes they would hoist the old flag in some remote area, and secretly watch to see who would respect the old traditions well enough to salute the flag of their former homeland when it looked like no one was watching to stop them. Typically, only strict patriots would risk their lives to honour their former country: so their loyalty to the old ways was clear, and they could be executed as traitors to the new regime with a clear conscience.
The management metaphor is likewise about finding out what someone's feelings on a given matter are, although the harsher elements are missing; one is rarely executed or even fired for giving an inappropriate answer in a board meeting.