Apple brings Picture in Picture multitasking to macOS Sierra. When watching a video in Safari or iTunes you can now float that video over the desktop so you can continue working on other things. The floating video screen can be pinned to any corner of you Mac’s screen and resized. However, you might encounter some issues when trying to go picture-in-picture with a YouTube video.
Other video services allows you to go Picture-in-Picture very easy. Vimeo for example has a new picture-in-picture control button, located next to the “fullscreen”button”. On DailyMotion, you can right click on the video while playing and choose “Enter Picture-in-Picture” from the menu.
But what about YouTube? Did you try to right click on the video while playing? Of course you did but you’ll get the same “copy video url”/”copy embed code” menu.
All you have to do to get picture-in-picture YouTube is to right click twice on the video while its playing.
That’s it. Enjoy!