While you won't be raised to greater heights merely on the basis of your correct wardrobe or mellifluous voice, these certainly help. So too does the style of the container in which you carry papers or lunch.
And people notice how your office is arranged, how you treat people in administrative pools, how you answer your phone (whether it's smart or dumb technology), how you come across at staff meetings, how you take praise and how you handle days when everything goes off the rails. Never underestimate the psychology of image. It's huge.
Tip: Decide what image you want to market. Presumably you want others to see you as clear-thinking, reliable, trustworthy, cheerful and good supervisor material, or some variation of a non-singing American Idol.
While you can't fabricate characteristics you don't possess, if you take the time to write an image description you can live with, doing so will reinforce your awareness of how others perceive you. As in marketing products, repetition is a basic rule of image building.