The distance-from-viewpoint threshold has also been reduced from 3000px to 1250px for faster connections like 4G and 4000px to 2500px for slower connections like 3G. These changes have been backported to users of recent Chrome versions (specifically 79-85), meaning that owners of devices with these versions will have the latest update at their disposal.

Google Chrome lazy loading loads only the content when you scroll and until you scroll down, the images would not load. This helps to save data and also helps to save on delays in the initial web site start ups. Google Chrome has supported lazy loading images since Chrome 76 was released a year ago. Google Chrome will also now support the lazy loading of iframe content. This means that third party embeds like YouTube videos and Spotify widgets only when the user scrolls down to it, helping to cut down on data and also boost the speed of the initial web page loading time.   References

Google Chrome s Lazy Loading Images Feature Now More Efficient   MobilityArena - 56