You Tube Videos in my Content Sidebar are Square

I embedded You Tube videos into a post (text, not visual editor) and chose Video for my post format. My content sidebar widget is set for Twenty Fourteen Ephemera Video. My videos look square and not rectangular like the examples on the demo site. They look as if they’ve been squished into a 4:3 format perhaps? I’m stumped. Help is appreciated. If you want to see what I mean, here is the link to the page we are starting: https://www.sunsetcarsblog.com