In many projects, [responsive images](https://www.smashingmagazine.com/2014/05/responsive-images-done-right-guide-picture-srcset/) aren’t a technical issue but a strategic concern. Delivering different images to different screens is technically possible with srcset and sizes and element and [Picturefill](https://github.com/scottjehl/picturefill) (or a similar) polyfill; but all of those variants of images have to be created, adjusted and baked into the logic of the existing CMS. And that’s not easy.