The windows runas command has a /profile switch that per help message specifies that the user's profile should be loaded.
What does it exactly load? What is understood by user's profile in this case? Are these just environment variables that can be seen with the set command or is it something else?
Read About User Profiles:
A user profile consists of the following elements:
- A registry hive. The registry hive is the file NTuser.dat. The hive is loaded by the system at user logon, and it is mapped to the HKEY_CURRENT_USER registry key. The user's registry hive maintains the user's registry-based preferences and configuration.
- A set of profile folders stored in the file system. User-profile files are stored in the Profiles directory, on a folder per-user basis. The user-profile folder is a container for applications and other system components to populate with sub-folders, and per-user data such as documents and configuration files. Windows Explorer uses the user-profile folders extensively for such items as the user's Desktop, Start menu and Documents folder.
Pay your attention to Local User Profiles and Roaming User Profiles explanation referenced there.
