Reputation is what we do when others are watching us.
Character is something we always do when nobody is watching us. We will do the right thing irrespective of any compelling situation.
Reputation is what people expect us to do next. It’s their expectation of the quality and character of the next thing we produce or say or do.
We control our actions (even when it feels like we don’t) and our actions over time (especially when we think no one is looking) earn our reputation.