A TYP file is a sort of "style sheet" for a Garmin map. It's the addition of a TYP file within your TalkyToaster GMAPSUPP that has changed the map display from the first of your images into the second of your images.
The TYP file that can be included into the GMAPSUPP from Lambertus (
http://garmin.openstreetmap.nl/) has a style based on the Mapnik style which is the default render for the OpenStreetMaps (OSM). Hence including the Mapnik TYP file into the Lambertus GMAPSUPP will make the Garmin map look like
OSM.
Without the TYP file included, the Lambertus Garmin map will look stylistically identical to the TalkyToaster map (first image) as both will be using the default Garmin GPS render.
p.s. It's possible to "correct" the Talkytoaster TYP file to display properly on your Garmin (by making the white lines thinner). It will require some software (
GMapTool) to unzip (and rezip) the TYP file from (to) the GMAPSUPP and an editor to change the TYP file content (e.g.
TYPWiz 2) ... and some computer skills.