I do not know what I did to make it so, but somehow I accidentally got Xcode Interface Builder to display a storyboard file in an undesired mode which displays the UI buttons, and text fields, in rectangles as shown in the screenshot below. How do I reverse what I did to get it out of this mode?
Story UI Buttons, & Text Fields, are in Rectangles
I found the answer:
In the "Adjust Editor Options" menu (the 5 uneven horizontal line icon to the upper right, just to the left of the "Add Editor on Right" icon) uncheck the menu items:
Layout Rectangles
Bounds Rectangles