Indeed, the Vic Premier is saying that when he gets some cases in his state - regardless of where they are from - he goes into lockdown.
The Lismore MP was pointing out a discrepancy from the NSW Premier to particular regions.
One area (Tamworth) has a positive visitor for a day, who leaves and no cases - lockdown.
One area (Byron) has a positive visitor for a number of days, stays and then becomes a case - no lockdown.
I don't see the sense in such decisions.
Edit: from ABC covid blog:
Northern NSW local government areas to go into lockdown from 6:00pm