The first thing I had to do was to pick the images I want to use and create four separate slide shows then convert it to Quick Time format as this format works better on Mac. Next step  was to create the patch in pd to play my movies.
I watched the tutorial 8: Playing a video in Gem / Applying a video as a texture to a shape, using the microphone to detect a sound a turning on and off a video file uploaded on http://www.amymarylucy.com/DIT_03.HTML and started to do my patch.

I wonder if there is a way to play a video without using an 'openpanel', 'open $1', 'auto $1' and bang each time I want to play my video but to point the video file once like when you use an image in 'pix_image' case... probably not because you have to tell pd which movie file you want to open and then tell pd to play it.
Another problem I had was how to stop the video looping. I found the topic on Pure Data forum and the patch 'video_no_loop'

So basically the way to do this is to sent a '0 message' to the right outlet of 'pix_film' and connect it to an inlet of the toggle. I tried and it works on my patch.

Then the next step was to find out how to make pd start to play the second video after the first stops. I've asked the question on pd forum and I got an answer: '[pix_film] has three outlets, the third one outputs a bang when the last frame is reached. you can use this to trigger an "open" message to [pix_film] and load another video. you'll also need a counter to find out which video to play.'
I wasn't sure if I understood it right but I tried and by using a logic I made it work!