I found that if I use Preview to open a PDF file, and use its tools to add text, or shape elements such as arrows, ellipse, rectangle, then I can use Preview to edit them.
But if the items are not Preview's, then I can't edit them. In this case, I have also tried using Adobe's Acrobat Standard or Pro trial version to edit a file, and when I see a person wearing a tie, with a shadow, I can move the tie to the left and move the shadow to the right (not always, for example, if the person with the tie is a pure image, then I can't).
So, can Preview have this capability? Why can I move element that Preview added to the PDF but not move other elements in the PDF?