Safari Bookmarklet for <video> Picture-In-Picture options – Copy the `bookmarket.js` snippet and paste it as the address of a bookmark in Safari. Then, while playing any <video> you can click the bookmarklet and the <video> will toggle between Picture-In-Picture and Inline.

bookmarket.js

javascript:var videos=document.getElementsByTagName("video");if(videos.length>0)for(var pipable=videos[0],i=0;i<videos.length;i++)if(!(pipable=videos[i]).paused&&pipable.webkitSupportsPresentationMode&&"function"==typeof pipable.webkitSetPresentationMode){pipable.webkitSetPresentationMode("picture-in-picture"===pipable.webkitPresentationMode?"inline":"picture-in-picture");break}

raw.js

var videos = document.getElementsByTagName("video");
if (videos.length > 0) {
  var pipable = videos[0];
  for (var i = 0; i < videos.length; i++) {
    pipable = videos[i];
    if (pipable.paused) continue;
    if (pipable.webkitSupportsPresentationMode && typeof pipable.webkitSetPresentationMode === "function") {
      pipable.webkitSetPresentationMode(pipable.webkitPresentationMode === "picture-in-picture" ? "inline" : "picture-in-picture");
      break;
    }
  }
}