A first strike happened at the last AGM. Could happen at this...

A first strike happened at the last AGM.
Could happen at this one and that's why the resolution on the spill has been included.
Here's some easy info from a Fairfax article:

The ‘first strike’ occurs when a company’s remuneration report — which outlines each director’s individual salary and bonus — receives a ‘no’ vote of 25 per cent or more by shareholders at the company’s annual general meeting.
The ‘second strike’ occurs when a company’s subsequent remuneration report also receives a ‘no’ vote of 25 per cent or more.

When a ‘second strike’ occurs, the shareholders will vote at the same AGM to determine whether all the directors will need to stand for re-election. If this ‘spill’ resolution passes with 50 per cent or more of eligible votes cast, then a ‘spill meeting’ will take place within 90 days.