Apple's new desktop software, MacOS Sierra, offers a way to watch a video while you continue to go about your business on your Mac -- and it's substantially better than attempting to resize a browser window just so. With Sierra's new picture-in-picture (PIP) feature, you can pop out a video from Safari or iTunes to a floating player so you keep an eye on it while you busy yourself elsewhere on your desktop.
Here's how MacOS Sierra's PIP feature works and its current limitations.
Safari or iTunes only
You need to use Safari or iTunes in order to use PIP, and only certain video players in Safari support it. Vimeo, for example, supports PIP. When you are playing a video in Vimeo, just click the button on the video player that sits between the AirPlay and full-screen buttons. The video will pop out of Vimeo and play in a PIP window in one of the four corners of your Mac desktop. You'll see the same PIP button when playing videos in iTunes.
Other sites don't support Sierra's PIP player, including Facebook, Twitter and Netflix, though perhaps these sites and others will add support in the future.
YouTube's video player doesn't offer the PIP button, but there is a way to pop out YouTube videos to the PIP player. Right-click twice on a video in YouTube and choose Enter Picture-in-Picture from the menu.
Sierra's PIP player can be resized and positioned in any of the four corners of your Mac. It stays on top of other windows, including full-screen apps.
When you mouse over the PIP window, three buttons appear: play/pause, close and a button to pop the video back from whence it came, either Safari or iTunes.
The PIP player lacks fast-forward and rewind buttons as well as a slider to scrub the video. You need to return to the video's tab in Safari or page in iTunes for such controls. You also need to keep the tab open in Safari or iTunes open in order for the video to continue playing in the PIP window.