It appears to my eye that the images are moving and fading in and maybe out.

No action scripting is required to get this to work.

The images need to be larger than the canvas. Import the first image. Using the points selection tool (top, right tools toolbar), select the top left, top right, bottom right corner points to the rectangle defining the shape that is filled with the image. You may need to change the zoom to 1/2. Move the points in so the rectangle is smaller than the image and the same size as the movie frame. To get the image moving effect, in one frame the image fill relative to the rectangle shape is in position 1 and in another frame (a copy of the first frame), the image fill is shifted relative to the rectangle using Transforms > Shift Image Fill.

The fade ins and outs can be achieved using the simple Fade/size effects under Effects menu.