Sharing second camera - I can't see what others are seeing

Click "show meeting" button.

By the "show meeting" button I presume you mean the tab-like buttons at top left when second camera sharing is on?

I don't seem to have the ability to insert an image here so I'll try to describe what I see.

First, in the Share/Advanced dialog there is an option to share a second camera.  There's also an option to choose one of several possible layouts.  I choose, for instance, the layout with the second camera full-size with the main camera overlaid at bottom left. 

After selecting the layout, in the main Zoom window there's a couple of tabs at top left with the labels "Meeting" and "My Camera".  Clicking "Meeting" shows the main camera with the background blacked out (and only the main camera), and "My Camera"  shows only the second camera.  I don't see anything resembling the overlay layout depicted in the Share/Advanced dialog.

Other participants describe a number of confusing results, such as both the main image and overlay being the same camera, and even THEIR feed window showing one of my cameras. 

So the question still stands, "how can I see exactly what participants see when I share a second camera?"