generator yo polymer grunt improvement to make your project getting smaller

grunt_after.json

{
    copy: {
      dist: {
        files: [{
          expand: true,
          dot: true,
          cwd: '<%= yeoman.app %>',
          dest: '<%= yeoman.dist %>',
          src: [
            '*.{ico,txt}',
            '.htaccess',
            '*.html',
            'elements/**',
            '!elements/**/*.scss',
            'images/{,*/}*.{webp,gif}',
          ]
        }, {
          expand: true,
          dot: true,
          cwd: '<%= yeoman.app %>',
          dest: '<%= yeoman.dist %>',
          src: [
            'bower_components/**/*.{js,html,css,webp,gif,jpeg,jpg,svg}',
            '!bower_components/**/{demo,demos,test,node_modules,templates,examples}/**',
            '!bower_components/**/{CHANGES,README,demo,Gruntfile,index}*.*'
          ]
        }]
      },
      styles: {
        files: [{
          expand: true,
          cwd: '<%= yeoman.app %>',
          dest: '.tmp',
          src: ['{styles,elements}/{,*/}*.css']
        }]
      }
    }
}

grunt_before.json

{
    copy: {
      dist: {
        files: [{
          expand: true,
          dot: true,
          cwd: '<%= yeoman.app %>',
          dest: '<%= yeoman.dist %>',
          src: [
            '*.{ico,txt}',
            '.htaccess',
            '*.html',
            'elements/**',
            '!elements/**/*.scss',
            'images/{,*/}*.{webp,gif}',
            'bower_components/**'
          ]
        }]
      },
      styles: {
        files: [{
          expand: true,
          cwd: '<%= yeoman.app %>',
          dest: '.tmp',
          src: ['{styles,elements}/{,*/}*.css']
        }]
      }
    }
}