This is a half rant / feature request…
The page for adding a background in SketchUp is just about the most useless this page could possibly be.
SketchUp allows you add image files to your model and position those images such that they act as a background. For example, you can have a single image placed vertically behind a house so that you can study what will be seen from certain angles within the house.
Really… We can’t get more content on that page? Like how to do said task?