As user @lelandfe pointed out here, Jampack is using browser native loading="lazy". There is currently no way to change this behavior but I could add an option

As user @lelandfe pointed out here, Jampack is using browser native loading="lazy". There is currently no way to change this behavior but I could add an option that would preload the below-the-fold images in the background when all the page is loaded. It's actually a pretty nice idea. I'm just afraid it will load unnecessary images at the bottom of the page but if it's an option, anybody can choose to have it or not!