Get PublishingImage field of a list using angular JS?

I don't think you can get it directly, but you can get it through FieldValuesAsHtml, but only if you query one and one item.

Something like this:

$http.get("/_api/Lists/GetByTitle('Articles')/Items").then(function (res) {
  angular.forEach(res.data.d.results, function (article) {
    $http({
      url: article.FieldValuesAsHtml.__deferred.uri,
      params: {
        $select: "PublishingImage"
      }
    }).then(function (res) {
      article.PublishingImage = res.d.PublishingImage;
    });
  });
});

You could also use $q.all to wait for the image urls to load, although there is no need, you can use {{article.PublishingImage}} in your template directly.
Note that the field will be encoded, so you'll need to either decode it or extract the url.