Does Spotlight offer lazy loading?
Spotlight actually has two types of lazy loading implemented.
Firstly, an embedded feed shows flashing boxes while the images are loading. This prevents the feed from appearing incomplete until the images load. If the preload option is not enabled in the Spotlight settings, the feed will load the images in the background while the rest of the page is loading.
Secondly, modern browsers have native support for lazy loading. Spotlight's embedded feeds use the browser's lazy loading to allow the browser to decide when it's the best time to load the images. Typically, that means that the images will load when they are visible on the screen. Desktop browsers may also load the images if everything else on the page has finished loading already. Mobile browsers that are using cellular data won't usually do this to preserve data. By leaving it up to the browser, we ensure that the most appropriate type of loading is used for a given device or scenario.