1/ Picture-I-Picture in macOS Sierra supports picture-in-picture — You don’t need Method 2 if you have the on-screen controls (a little button at lower left on your video player) but if that doesn’t appear (I hardly ever see them), there’s another way to enable PiP mode. On, say YouTube, right-click in the middle of the movie to bring up a set of YouTube-supplied HTML 5-based controls. This takes doing it to get it, but once that pop-up menu is on-screen, right-click away from it (right of t, or left, or above or below) and another pop-out menu appears, as above. Choose that, and the movie will unfold and snap to the nearest corner of your Mac desktop. You can only access this particular Sierra contextual menu if the HTML 5-supplied pop-up menu is on screen first.
2/ Use Command-drag to position Picture-in-Picture videos — If you’re watching a video in picture-in-picture mode in macOS Sierra, it snaps to the nearest corner. Even when you drag it out of that corner, it will again snap to the corner nearest to where you let it go.But hold down the Command key while you drag to put the video where you want it. Iif you Command-Drag the video, it stays where you leave it. If you don’t, it will snap to the nearest corner.
3/ Siri to search for images on the internet — macOS Sierra’s voice assistant can search the web for pictures. Click on Siri’s colourful Dock or menu bar icon, and say something like ‘Do a Web search for images of [whatever]’. The list of results that appears is interactive. For example, you can drag and drop one of those thumbnails out to your desktop to save it there, onto Mail’s icon in the Dock to attach it to an email, or into a Pages or Word document to insert it. You can also right- or Control-click a thumbnail to get a few other options, including the ability to copy the image.
4/ Using Photos Memories — The new Memories feature within Sierra’s version of Photos is a pretty cool way to look back on the pictures you’ve taken. Depending on how big your Photos library is, the program will generate up to three new Memories per day to remind you of events or places in your life. You can look at these Memories by choosing that option either under the big buttons near the top of Photos’ window…
Selecting Memories in either place will show you both the automatically-created ones and ones you’ve made.
5/ Make a Memory — This is easy, if not very obvious: click on the header for any moment, collection, or year within the main Photos view, and you’ll see an Add to Memories option at the bottom of the following screen.
Once you’re looking at all of your Memories, then, you can double-click one to check out the images within it or use the Play button to view it as a slideshow. If you see a Memory you really like and would like to keep, you can ‘favorite’ it. Choose Image>Add to Favorite Memories… or right-click on the Memory and select that same option.
To remove a favorited Memory, select it and choose the Remove from Favorite Memories option from the Image menu, or right-click on it again and pick that from the contextual menu.