In Impress,picking any individual object is very difficult under some
circumstances. e.g. when the object is almost transparent (see Issue 80387) or
overlapping with other objects, or in a dense cluster. 

(Selecting a desired shape by repeatedly pressing TAB is very cumbersome.
Besides, if you want to select several objects together, you cannot use this
method at all. You HAVE to use mouse to pick your objects.)

A far easier method would be to click on the objects listed in the Navigator and
see in the pane to check if we have picked the correct one. If not, just click
again to de-select it. You should be able to use CTRL+click to select several
objects together (to move them together, to group them, etc.)

But the problem here is that the Navigator does not list objects created in
Impress, or objects inserted from outside. 

In comparison, Writer's Navigator does list all objects.
In addition, there is a pending proposal (Issue 15297) that in case of inserted
objects, the filename be shown in Navigator.

The Impress Navigator too must follow the same logic: 
1. Provide automatic names to all shapes/graphics; and 
2. In case of inserted graphics, put the filename in brackets.