Object type
From MTG Wiki
Enterprise analyzes each kind of file in the system and assigns it a type based on its file extension. That object type determines which icon the file uses in Enterprise systems.
For instance, Content Station and Smart Connection know that .jpg, .pdf, and .tif are images; we have given those kinds of files custom icons to make life easier for the art department.
Why it matters
A dossier and an article need different statuses to move through our workflow. Object type determines which statuses are available for each file.