Using Shapes in nadir

I put this in a resolved issue not realizing it would not show up, so am posting it again.
Regarding adding Shapes into a scene.
Is there something to describe how this is done? I have been trying unsuccessfully to do this. One time I managed to get a small picture to show up, but it was distorted. I have not been able to even get a distorted picture again. I see the small locater appear on the preview, but the image does not appear. If I then attempt to move the picture it disappears never to be seen again. I have found playing with the xyz settings I can see it, but moving into position seems impossible or random. Help!
Any videos that show how this is supposed to be done?
Thanks!