Collection Repeat don't display images

i really need this help am running our of idea. am creating an app that would display all images that which are downloaded and unzipped then i generated a url for all of the images.
the problem is if i use ng-repeat on ion-slides the images would show but it would stack the images and i wont see the other images even when i scroll. And if i use collection-repeat no single image would show in the ion-slides. please below is the code pen i created i really need this help please