I had similar issues but found a solution. The application has a bug where you specify the absolute location of the image on your website during testing and creation that works well. But when the code is published those links are all made relative. To correct this you have to look for the variable definitions in your published code are fix the links. Here is an example where I fixed it.
Google Web Designer image location:
http://greencoconut.nl/wp/wp-content/themes/origami-paper/animations/0-bird_1.pngPublished code generated by Google Web Designer:
var bird$Config$ = {"src":"0-bird_1.png","id":"bird"};
Fix:
var bird$Config$ = {"src":"
http://greencoconut.nl/wp/wp-content/themes/origami-paper/animations/0-bird_1.png","id":"bird"};
You have to do this for all the images and then it works again. Or you move it to the same folder as where you have your page where you load this. But that won't work if you have a WordPress blog for example because then it will look for an image located in the folder that you find in the addressbar. So it is better to hardcode this. A bit painful but we should not complain when you take into account that the software is free and generated nice animations in a very short time.