They exist as a compliment and the more I study craftmanship, the more I realize their restriction allows the artist the ability to think. Although there are many types of elaboration in architectural design far beyond these profiles, they provide the basis of milling technology.
In this particular artwork, there is a cove in the vanity legs, a small bead in the vertical woodwork, probably a cove on the raised panels in the medicine cabinet doors, and a 45 degree angle cut on the horizontal wainscoting to help the eye accept the joinery, otherwise without this small straight line profile, the eye would see variations in the gap, and the brain would not as easily accept it. By adding what is called tongue and groove to the joinery, the eye accepts it as the joinery is smoothed for the mind. The gaps in the inset doors and drawers on the vanity are made consistent otherwise the mind sees the imperfections.