Browser behavior is varied for loading attribute?

In my tests I saw that in Chrome + Edge my image requests were firing off when the image was one full viewport or more above the image. In Safari even more. I have an image to illustrate but medium won't let mw add images to responses so … https://gcdn.pbrd.co/images/ckhhf0oRFvAV.png?o=1 the arrows are images not in VP being loaded by safari.

Also great post! Thanks for sharing.