Hey Armin.
What about featuring these stacked images like in the link below. I see it many times on "contemporary webdesign" and I like it alot. Maybe really simple for as an extra option for the image slider? When you open it all images are stacked and by clicking one the top image disappears? Or even the other way around like shown in the link.
http://www.austenezzell.com/?time=short
What do you think?
Have a good one <3