Internally aem stores all the renditions inside the asset names.Examples [A]. When you map in drive you can;t have filename and foldername same. It is operating system limit. Hence only original (/content/dam/geometrixx/portraits/scott_reynolds.jpg) is shown in webdav clients.
[A]
/content/dam/geometrixx/portraits/scott_reynolds.jpg
/content/dam/geometrixx/portraits/scott_reynolds.jpg/jcr:content/renditions/cq5dam.thumbnail.140.100.png
/content/dam/geometrixx/portraits/scott_reynolds.jpg/jcr:content/renditions/cq5dam.thumbnail.319.319.png