Hi @marc,
Sorry, I don’t quite get the idea here. At the beginning you mentioned that you are choosing between 2 images. Do you just take the 2 latest ones? Or what other logic are you using?
Or you want to present 1 image at a time?
As @pford mentioned, one of the solutions could be to create the custom list with image & the button(s).
But if you would like have an Image Slider with 2 images + 2 separate buttons (choose 1st / choose 2nd), then you will need to somehow link this button to the images. This could be done with the help of single-item lists (you convert each button to the list, filtered by the image). But the problem here is that you need to know some kind of ID for each of the images. And whole set up becomes pretty complicated.