Do you have a specific example image you could link me to? I tried a random page with 5 images and all of them just opened a lightbox. And I had trouble closing the lightbox too; not that its related to the purpose of the example.
It just astounds me that something so basic, an image with a link, does not just work by default.
That's only basic from the perspective of a desktop screen. UXR shows mobile screens bring with them entirely different usage and expectations, and a change in mentality is needed to present your content.
I checked the page. Clicking the images while in mobile view does not bring me to the page as you claim. Rather, it brings-up a larger version of the image. Are you sure you have been testing these wikis in mobile view?