[dgb23]

You typically don’t have a lot of breakpoints for image sizes. Maybe 2-4 is typical.

But yes, since you already know the possible proportions and sizes you want to resize/crop/scale etc. on the server, and deliver the correct image via a picture element. The browser then fetches exactly what it needs.

This css property is however useful if you want something more dynamic and you don’t know or don’t care to know beforehand how the image will be cropped.