Added
- Dia-style picture-in-picture. At rest it's just the video. Hover it and the video dims to show Back to Tab and Close at the top with the site's name between them, big 15-second back / play-pause / 15-second forward buttons in the middle, and a thin progress line along the bottom. You can switch back to Firefox's own controls in the settings.
- Tuck picture-in-picture away. Press the tuck button beside Close, or drag the window against the left or right side of the screen (a blue edge says "Let go to tuck away"). It slides off, leaving a thin strip with an arrow. Point at the strip to peek the video back out; it tucks away again when you move off it. Press Keep it out or drag it away from the edge to leave it out.
- The music player's picture-in-picture button now always shows. Zen only showed it when a page had exactly one video, so it never appeared on YouTube.
Fixed
- Typing an address no longer flashes between the site's icon and the magnifying glass.
- Results in the address pop-up show the site's icon instead of a blank globe when the icon is saved under the other form of the address (youtube.com vs www.youtube.com).