Landing page video thumbnail not autopopulating

Why is the video thumbnail at the bottom of this page not autopopulating? The thumbnail only shows when they click play, which isn't usually the case.cWe have a image thumbnail link in the marketo landing page variables and the embed link. 
Here is the preview link. it.recastsoftware.com/lpeditor/devicePreview?p=3497&t=q5c3my3oev7iinfIkIxhCw,,&m=563-ODB-688