Videos not running?

Hello there!

I’ve got the “show video posts” box checked in my tumblr widget, yet all that shows up appears to be the first frame of the video which never plays. There is no play button, pause or volume control that I can see. It also doesn’t work as a link to the post on tumblr, so without users navigating to my tumblr page, there’s no way for them to watch the video while still on my web site. Help?

https://wordpress.org/plugins/tumblr-widget-for-wordpress/