has an idea and makes something. interests of users and producers do not play a role. she does not start with a specification. big changes of the product are possible throughout the whole creation process, also short before delivery. The interpretation of the result comes only in the end. It is ok if others give it a different interpretation.
scenario(s) -- communication
scenario(s) -- creative industry
the designer gets a much less specified problem, or she has even to invent a problem. he comes pretty fast with a prototype, evaluates the prototype, rejects it or improves it, and comes with a new prototype. doing this, he explores the design space, and eventually she will come with a final product. different interests as aesthetics, simplicity, usability, easy productions are relevant design criteria for the designer.
the engineer gets a problem she has to solve, in the best case as a complete specification. the engineer solves this problem with the means he has learnt, starts with a decomposition, applies standard solutions when possible, invents new solutions when necessary. when finding new solutions the engineer uses in most cases "incremental design", meaning that starting from an existing solution by modifications a new product is made. Less often, an engineer has to apply "radical design" which means inventing something new with no similar thing to build upon (e.g. the first space ships). the engineer tries to finish a prototype early enough to have time for testing, and, if necessary, improvements for the final product.
scenario(s) -- entertaiment
scenario(s) -- game development
scenario(s) -- product design