Can I get help creating a snippet to have unique images on the mobile version of the website and desktop version?

Site URL: https://www.caseygatesrolfing.com/rolfing-modalities

Can I get help creating a snippet to have unique images on the mobile version of the website and desktop version? 

https://www.caseygatesrolfing.com/rolfing-modalities

First image block is for mobile, the second image block is for desktop.

Thank you!

You can use a media query to hide and display different image blocks on mobile/desktop, something like this:

// Blocks to hide on desktop
@media only screen and (min-width:750px) {
  #block-yui_3_17_2_1_1662597656415_29097 {
    display:none;
  }
}
// Blocks to hide on mobile
@media only screen and (max-width:750px) {
  #block-yui_3_17_2_1_1661988335368_69640 {
    display:none;
  }
}

Add new block IDs separated with commas as you need more instances.