Much more metadata when using DNG converter; source?

My workflow varies between:

1.  Downloading the raw (NEF) files directly from the memory card to my hard disk.

2.  Using the DNG converter to download and convert the files from the memory card to my hard disk.

When looking at the metadata embedded in the image files (ExifTool) I note there is a large amount of data present in the .DNG files which is absent from the .NEF files.  Presumably this data is added by the DNG Converter.  I am particularly curious about the data relating to Camera Profile.  Can anyone enlighten me about the source of this data?

Thanks.