For the guys, its an oily face that leaves shine from the lights and for the women, its the right makeup and the amount to put on for studio lights. Why do you think in the TV shows they all have make up on.
Properly done by a professional make up artist it isn't obvious and enhances your features. In fact most clients say it relaxes them by talking to the trained make up artists about the process and watching the photographer in your office or boardroom at work.
From my experience in the corporate world, if you want to invest in time and money to have your portrait done, think about what the make up can do for your face. We do retouch marks, some wrinkles, whiten the teeth and eyes so your portrait will look fantastic.