My suggestion is if you have something masked in photoshop you will see the background and the frame of the image. The background could have color or be transparent. The frame has asset information and a ruler if needed. See Normal Working area screenshot attached.
What if you could make the background and the frame see through? To see perhaps another application running or the desktop? I use "see through" not to confuse the word transparent. See Suggested working area screenshot attached.
If I were needing some image from another app or desktop one way I would make a screenshot or open another image and stack in layers under the outlined image. It will still be incased in the frame. If I was able to "see through" the frame and background, I could use photoshop in so many new ways.