It starts at a random question ( so all the answers are evenly distributed) and it just loops around to the start. I do plan to add an 'end' page with a summary at a later stage.

I hadn't used Pixabay before but it was perfect for this. It was a bit of mucking around to have 3 different image sizes for each question -so yes that took a while. About 6 hours including the domain and server setup I would say. The code was the easy (and fun) part.