The Embed block (#316) appears to work well up until a video is actually embedded, at which point it looks as though clicking the block will start it playing. Even though that won't be the case (we should port the click interceptor that's in WordPress now), the UI observation still stands.

What's a good approach to make this interface less obtuse, so we don't frighten users from clicking the block? Let's discuss. Some ideas:

• Abstract live preview for the block — don't show 1:1 what it will look like, perhaps include a generic border with meta information
• Add a clickable UI fixture permanently docked near the embed
• Add a clickable UI fixture that shows up on hover