You can use the nudge shortcut in PowerPoint to move objects by a few pixels. This tool, along with the powerpoint Align tools, are one of the most powerful tools for presentation designers toward making pixel-perfect Slides. Moving the objects and powerpoint shapes by small pixels let you control more precisely the position of a object within the slide.
To move an object slightly in powerpoint for Mac, press CMD+arrow, where arrow is the direction where you want to move the object. So if you want to move up the shape in powerpoint slightly press CMD+Up Key. More useful keystrokes can be found here.
In some situations, it is possible that the shape jumps more than a single pixel. If the nudge keystroke is not working for you, then we’d suggest to check the View -> Guides and make sure the Snap to Grid option is unchecked.