Earlier quoted context omitted.
Normal way to achieve img to have a size before the resource in src loads is to set width/height attributes to the native size of the resource that will be loaded (because you have to tell the browser size of an image somehow), and if you want to scale it with aspect ratio preserved you just use min/max-width/height in css to fit it to whatever size you need.
You’d think, right? But I tried that approach, and I don’t remember what the issues were but there were problems. Unless I was doing something wrong. Either way, yes, you need the dimensions ahead of time, which is reasonable and not my gripe.
Probably this, that approach is very standardized now across the major browsers.
I worked at a web agency until last year, and led projects to inline image height/width values for 4 large companies. Huge reduction in CLS and permits you to lazyload without fear of layout shifts.
`aspect-ratio` hadn't landed in iOS Safari at that point, but you can do that instead now. Identical behavior.