She says illustrators may have strong emotional ties to their work. When they retire, they are likely to paint. Their style is a bit more business-like. Of course both have elements and skills of the other. That is why both illustrators and designers are vital.
Some projects depend on both.
An illustrator made the first stab at the poster, drawing a child's exasperated face dotted with spots. Then a designer took over, switching the background from white to black, converting the grey lines to green, and splattering the face with neon pink spots. Brown says that a new dimension has been added to medical illustration by computer technology but that computers are not for everyone. Some people get a real charge out of working on the computer, and it does not interfere with their creative process. It must be cerebral, intellectual.