Yes, you may be different person in your personal life or for other people but you will have different reputation at your work. It is due to the people you are surrounded with.
If you work with those people who are different on your face and different on your back, naturally your reputation will change accordingly.
You may be a peaceful person at your personal life but spending time with those kinds of people who are dishonest and biased at their work, it is natural that your attitude too will change. Either you will agree with them or oppose.
So for me reputation is what you get from your surrounding. It is just a mirror and reflection from others.