Can I disable background screen from video frame on Youtube and enlarge the actual video?

Lately I have been seeing lots of videos that play in a very small frame in the corner, while a static ad or a background that looks something like a

Lately I have been seeing lots of videos that play in a very small frame in the corner, while a static ad or a background that looks something like a screensaver, plays behind it. I have vision impairments and find it very difficult to see the actual video I'm trying to watch with this sort of configuration. Is there some way that I can play these videos in a normal screen at regular size with no background ?
Thank you for any information and assistance !

or:Lately I have been seeing lots of videos that play in a very small frame in the corner, while a static ad or a background that looks something like a screensaver, plays behind it. I have vision impairments and find it very difficult to see the actual video I'm trying to watch with this sort of configuration. Is there some way that I can play these videos in a normal screen at regular size with no background ?Thank you for any information and assistance !

Tags:video,background,