You can create this effect with your own photos.
Download this zip file.
Save and unzip where you want it.
Here is how to unzip the file.
Copy your photos into the Show Folder!

Load this show. Double click on the first slide.

Click on layer settings. Then right click one of the photo slides.

Select File

Click on your photo. Click on the other photo in the layer list

And select the same photo

OK. Now you have changed both photos in the one slide.
Click once on the slide to select it. (turns blue)
Right click the slide and hit copy.

Click on the next empty slide and hit paste.

Now repeat the steps and change the photo again.

This shows the directions, how easy it is.