Photos that are a 'highlight' in your album cover the full width of your album. If you scroll by the photo it will animate for you to be able to see the full image without scrolling too much.
Turn animation off
If you do not wish to have this animation you can turn this off. Click on the pencil icon to open the 'edit and enrich'-mode. Then click on the photo with the animation and uncheck the box saying 'animated view'.