You can see that there are 3 images before “50 Show all” in the slider.
If you click any image the Popup will open. let us say that you click on “Prime Minister Theresa May” In the Pop-up mode same image will open How is this being managed? Some similar ID’s method?
Inspecting the image link, I see in the event listener section that there are several click events handled by it, including a click handler for each gallery link.