Report design - Layers - inaccessable item in visual layout editor

In the visual representation a report design, there was a Shape element that had a String element inside.
I could not click the String element to see its properties, because every time I clicked it, the Shape element was selected.
It seems that they are layered, where the Shape elemement is on top of the String element.
In the AOT, the sequence was:
...
Shape element
String element
...
When the order in the AOT was changed to this:
...
String element
Shape element
...
then the String element was selectable.

Conclusion:
The sequence of the elements in the AOT determines which item is on top.
The top item in the AOT is on the top layer in the visual layout editor.
The bottom item in the AOT is on the bottom layer in the visual layout editor.