A Headline Picture Moves Down as I scroll on websites

When I go to a site, for example, Fox News, and click a story, often there is a picture at the top with an arrow in a circle (which means it is a video) and as I scroll down, that picture moves from the top and goes to bottom right of my screen. Once there, I can click the "X" and close it, but this behavior seems new and is very irritating. Has some preference gotten changed, or is this just something that web sites are doing now and I cannot escape? Any help would be greatly appreciated.

I am using a MacBookPro, late 2013 edition with retina display, and am totally current on all updates for both system software and Safari.

Thanks!

Brian