Stream video spinning circle

While this does not happen for every user, a couple of people in our advertising department especially are noticing that when viewing a page with a video embed, there is a constant spinning circle over the video thumbnail. As soon as you click play, it goes away, but until then, the circle spins and spins over the thumbnail image.

The embeds are not set to preload, so I am unsure why it continues to spin and appear to be loading?