OverPicture is a Safari Extension that allows you to play any web video in Picture-In-Picture mode.
You can enable Picture-in-Picture for any web video the following ways:
• Click the Picture-in-Picture toolbar button.
• In selected players like YouTube use the custom button.
• Press the P key while playing a video.
Note: You can enable the OverPicture Extension from the Extensions section of the Safari Preferences pane.