Final answer:
Supplemental services in design work can involve extra design elements, while additional services can include project management.
Step-by-step explanation:
Supplemental services refer to additional features or options that are offered alongside a main product or service to enhance its value or performance. Examples of supplemental services in the context of design work could include extra design work such as creating additional graphic elements or adding more detailed renderings.
On the other hand, additional services are those that go beyond what is originally provided as part of the main product or service. In the case of design work, an example of an additional service could be project management, which involves overseeing the entire design process, coordinating with different stakeholders, and ensuring the project stays on track.