Defer Offscreen Images
Why stress out the browser with unnecessary downloads which slows page load and causes havoc with user experience? Offscreen images
Offscreen images appear on the page below the fold. Since most users initially enter a page above the fold, there is no need to load that image until a user scrolls to or approaches its location on the page.
Defer loading these images until needed to speed up page load and TTI.
Deploying deferment
Instruct your pages to only load above-the-fold images upon initial page load. Lazy loading images as well as other below-the-fold content such as JavaScript, HTML and CSS. Using an intersection observer can be useful here. And, please lazy load video below the fold.
There are a number of JavaScript libraries that help those who can freely edit their html code. Many CMS programs such as WordPress offer plugins to implement the lazy loading process.