When you need an image to exist when your styles are processed by ember-cli

Brocfile.js

function AssetImporterPlugin(options, appName) {
  this.name    = 'yapp-asset-importer';
  this.appName = appName;
  this.options = options || {};
}

AssetImporterPlugin.prototype.treeFor = function treeFor(name) {
  if (name !== "styles") { return; }
  return pickFiles('shared-assets', {
    srcDir: '/images',
    destDir: '/assets/images'
  });
};

app.project.addons.push(new AssetImporterPlugin(app.project));