Requested feature overview description: A separate dropdown for video width opposed to image width

Why would it be useful? WebMs tend to not be any wider than a widescreen monitor unless they're also taller than it, so scaling them to fit vertically works much better for some users, while they may also appreciate having tall comic pages scaled horizontally since they're built to be read top to bottom.

What part(s) of the site page(s) are affected? The user settings and any post page