The author level provides space to address the students personally and to give them (didactical) information, for example:
greetings at the beginning and parting words at the end
an introduction to the subject of the case
information that is related to a learning setting (topics and questions to preparate for a course, etc.)
a summary (in the middle/at the end of a case)
references
learning objectives/goals
a photo of the author or the author's clinic
etc.