Well if a user has its firefox window opened in a small size, he will experience that problem, too. So first of all I want to solve this problem with firefox and of course I don’t want to have this problem on any mobile device, too.
Hey, this link just shows you how to download someone’s thumbnail on youtube.
I had to find that out for myself a month ago, too. You can set a custom thumbnail on youtube. I uploaded a big .png in the same aspect ratio as the video-resolution and the quality is very good. This isn’t a theme issue 🙂
