- Go to the Picture-in-Picture Extension (by Google).
- Click Add to Chrome.
- Click Add Extension.
Find a video you want to watch.
- Click the picture-in-picture icon in the Chrome toolbar.
- The video will pop out and keep playing while you have different programs open.
You must keep the original video tab open in Chrome to watch in picture-in-picture.
Thanks to LifeWire.com for the detailed post.