The Status Report checks every song to see if it currently has metadata for the fields listed in Show these fields in the Status Report, by default a small subset of the fields supported by SongKong are listed.
Songs are always checked to see if they have embedded artwork, and you can use the Show artwork at least this size option to show artwork larger than a particular size, this allows you to determine how many songs have high resolution artwork based on your own idea of high resolution artwork.
Once you initiate Start SongKong will begin counting your metadata completeness, creating a UPnP Control Point style browser to browse your metadata by artist/album/composer/work and folder and creating a metadata spreadsheet containing all your metadata.