This is basically the Swiss system where the British public can have a vote to approve or veto any law or proposal on any subject and their decision takes precedence over any other law or decision made in either the UK or any other place.
Why does this idea matter?
This is true democracy in action. It means that the British people can have a direct input on the direction of the government of the day. It also safeguards democracy for the future by giving the people a veto over any proposed laws to limit freedom of speech etc. e.g.
The one way treaty with America on extradition.
Banning the burka or other head covering (except in places of worship) on security grounds.
Removing discrimation laws against Catholics being the Monarch.