As a loader, it loads the bytes file and builds the IDA database using the contents of the XML file.
As a plugin, it will add information to an existing IDA database. It will NOT load any binary data from the bytes file. It will add symbols, comments, code, data, functions, etc. for addresses that currently existing in the database.
Currently, the loader does not support importing memory overlays or Harvard architectures (e.g., 8051).