Hide title & controls on embeds for better visual integration with page content

[skoolbus39]

Currently, MediaHub embeds show title and controls when content is not playing. Instead, show only poster frame and play button, and continue to access controls on hover.

Hiding the controls—and showing them only when needed—will better visually integrate the embeds with their surrounding content rather than giving the effect of being shoehorned in or bolted on or pick your own metaphor.