How can I do this effect using Sony Movie Studio (described in the description)?

I have three images, I want to show one of the images in full screen first, then introduce the second image so that both the images fit half of the screen (as the first one is pushed away), then introduce the third image so that all three images are evenly shown on screen.

Sorry if that's hard to understand, I don't have an example to show.

Thanks for reading.