A good designer can design for any application, so yes it is. Based upon the principle is that the Designer must understand the technologies displaying the data from Drupal. An understanding of how the Drupal front end works is extremely beneficial and communication of the designer with the solution architect is paramount to successful deployment. Without the designer understanding the full stack technology which the solutions architect. The UI layout is critical and how this is implemented is a collaborative solution although a good designer will also have prerequisite knowledge of the UI patterns and heuristic knowledge of the user experience involved for example.