Hi, thanks for your question about different models of representation.
While the terms delegate, partisan, trustee and mirror are not commonly used to describe representation, they do relate to four different ideas about how members of parliament represent the people who elected them. Three of these cover ways that an elected representative might approach their work:
Mirror representation is the idea that an elected body of representatives should reflect society’s different groups in similar proportions to those that exist in the wider population. Examples of different groups could be people of different social, religious or ethnic backgrounds.
There is a parliamentary library paper which goes into greater detail about different models of representation.