Image sizes for different breakpoints

So, I’m a bit confused even after using Webflow for over a year now. When I see marketing materials of webflow it says: loading web pages 10 times faster because of automatic rescaling for different breakpoints.

But when I analyze my page with google page insights, it says that my image sizes are not optimized for the current breakpoint. How do I go about fixing and improving my sight speeds then?

Am I supposed to manually edit and upload all images for each breakpoint on every page and sub-page?


Here is my site Read-Only: [LINK]Webflow - elumico_final1
(how to share your site Read-Only link)