When Collins speaks of "window and mirror maturity", he means that the "right people"...

Take responsibility for difficulties $("$look in the mirror"$)$ and give credit to others for successes $($are a "window" to showcase others$).$

Keep $100\%$ of their commitments, or do not commit in the first place

Share$-$ and are passionate about$--$ the organization's core values

All of the above