Without black bars ?

With black bars ?

PS 1 : I try hard to find a solution.  Unfortunately, the wordpress.com teckies insist that this cannot change since this is a global function and  blah… blah… blah …

PS 2 : When on my site, and not on the wordpress backend, there are no bars on the first video.  You have to hover in order to see the bars with the description.  I want the same effect when on backend. This is a tiny accomplishment. Cheers Outosego !