Hi @nuetige, set the width of the image to 100%. The image should be having at least as much width and height as the div block in desktop mode, if you do not want it to stretch. I would create your images to be the same aspect ration as the div blocks.
If you have a specific design with this setup already, can you please update your post with some more information so we can help you faster? Things like your read-only link, and screenshots of the elements in question really speed things up.
Posting guidelines can be found here: Posting Guidelines for the Design Help Category - General - Forum | Webflow
cheers, dave