The sass loader doc says: "If you're just generating CSS without passing it to the css-loader, it must be relative to your web root".
So i did as it tells, I have my index.html in my project root, then I'm trying to load an image from my scss file.
Now I have 2 errors: 1) from Chrome's console: Cannot find module "./img/header.jpg". 2) from my terminal: 
ERROR in ./~/css-loader!./~/sass-loader!./~/resolve-url-loader!./public/css/header.scss
Module not found: Error: Cannot resolve 'file' or 'directory' ./img/header.jpg in C:\Web-Development\React\Portfolio\public\css
 @ ./~/css-loader!./~/sass-loader!./~/resolve-url-loader!./public/css/header.scss 6:64-91
webpack.config.js
module.exports = {
    entry: './main.jsx',
    output: {
        filename: './public/js/build/bundle.js'
    },
    module: {
        loaders: [
            {
              test: /\.jsx?$/,
              exclude: /(node_modules|bower_components)/,
              loader: 'babel',
              query: {
                  presets: ['react', 'es2015']
              }
          },
          {
              test: /\.scss$/,
              loaders: ["style", "css", "sass", "resolve-url"]
          },
          {
            test: /\.jpg$/,
            loader: "file?name=[path][name].[ext]"
          }
        ]
    }
};
If I see my code, I can clearly see that my css lives inside <head> so I've pointed my image's path to my root, as documentation says, but still can't fix it.
UPDATE:
I've installed file-loader and followed the instructions, now I get this error in console: GET http://localhost:3000/public/img/header.jpg 404 (Not Found) - jquery.js:9119
 
     
    