Did you try an text editor . Svg is a textual vector format. Your first image is a real svg. The second is an embedded PNG in a svg. So no real svg and that might explain the problem. Having these embedded images in svg means it’s basically just an image. I think you need to look for another way to covert images. Take a look at this stack overflow answer for tips about converting images:
One of the answers is http://www.inkscape.org/. This is a really nice open source product. In general I think is difficult to covert images to vector unless they’re plain drawings without all kind of effects. In general I would opt for trying to find svg images. Or edit svg with, like the Kodi image. Edit in inkscape or in a xml aware editor. Svg is xml. Just do some trail-and-error by deleting parts and see what happens. Although that can take up some time to get it right