Resize picture zone in MacOS Preview

Adding blank space around an image, by resizing the zone of a picture without changing the size of the image itself in MacOS Preview app, is not possible natively. However there is a workaround:

  1. Open the image in Preview
  2. Select all the content with Cmd+A and copy it with Cmd+C
  3. While all is still selected, delete the image with Del
  4. Resize the zone to the desired dimensions in Tools > Adjust Size
  5. Paste the original image with Cmd+V and reposition it if necessary
  6. Save the file