Wow, what a detailed answer, thank you! Sadly (as you have already guessed), there are several images in the child pages and I would like to have an entry for each of them, so looping through the pages alone isn’t going to work. 
My content structure looks somewhat like this:
- Screenshots
- Project a
- image1.jpg
- image2.jpg
- Project B
- image3.jpg
- image4.jpg
- Project C
- image5.jpg
- image6.jpg
- image7.jpg
Your code is perfect for a Blogfeed though, and I’ll probably use it for that, since it works fine. It’s just not working for my initial idea. And I’m aware that my structure may be pushing the plugin a bit, so if it really isn’t meant for looping through images, I guess there isn’t much I can do to achieve this?