Suggestion to move the play button overlay, into the bottom-left corner, and increase the contrast for the pre-mouseover state, similar to the example from http://www.bbc.com/news/business-30016007
Context: The current location obscures the center of the thumbnails, which drastically reduces their aesthetic and functional use as still images.
This has led to videos being moved down from the lead-image position (with actual still images as replacements).
It is also often hard to see the play button, because we've purposefully lowered the contrast due to the overlay being in the center. (cf. bug 48377 ("Videos' [Play ▶] center triangle: Improve contrast so it's easier to spot that it's not a still image")
This has recently been discussed at
(Tangential see also for bug 62369)