Why separate svg extension in webpack-isomorphic-tools config?

[gsccheng]

In the config, you can see that svg is configured separately in the assets:

svg: {
    extension: 'svg',
    parser: WebpackIsomorphicToolsPlugin.url_loader_parser
 },

Why is that? When I added it to the images extensions, the app still seemed to load fine:

assets: {
    images: {
      extensions: [
        'jpeg',
        'jpg',
        'png',
        'svg',
        'gif'
      ],
      parser: WebpackIsomorphicToolsPlugin.url_loader_parser