Learn some Shortcuts programming by following along and building a Shortcut that adds a border and caption to a photo file and saves it as a new file.
There is no simple built-in command to center a window on a Mac. But you can use other techniques. Learn how to combine two window movements to center a window, or use scripted Shortcuts, or a third party app.
Learn more about creating your own Shortcuts by following along with this watermark tutorial. Build a Shortcut that will add an overlay to an image file and save the file to the same location with a new name. This can be the basis for all sorts of image modification Shortcuts.
You can create a Shortcut that will allow you to capture a portion of your screen, and then the text from that image will be extracted and placed in the clipboard. This is useful where you can't normally select and copy text from websites and apps.