Hi Jared and Matt,
Are you guys creating the ad for DoubleClick Studio environment?
In GWD, we do add the following the link in the preview file to stimulate the Studio Preview environment, so that is probably why you notice that the images and animation show up immediately:
<script data-exports-type="dclk-quick-preview">studio.Enabler.setRushSimulatedLocalEvents(true);</script>
However this line is not needed for the published file when you publish the file to Studio (Publish Locally or Publish to Studio) because Studio will take care of the preview correctly from the Studio environment.
Can you upload your creative to DoubleClick Studio and preview in Studio?
Thanks,
Emily (GWD Team)