Yes Denis, how to differentiate a slide N°1 and a slide N°2 which has two identical images to that of N°1 in "Object and animation", it makes us 3 identical images in the project.
10, 20, 50 slides is manageable but 300 or 400 slides you can make duplicates, you have to view several to be on your editing.
Maybe our dear programmers could add a function that would indicate the number of times the image is used
Good WE