First things first, download the Chrome extension Squarespace Collection/ Block Identifier.

The code you will be using is:

#block-yui_whatever{margin-top-150px}

Want to see a video tutorial of how to overlap a photo on Squarespace 7.1? Watch below!

To hide some of the spacers on desktop that you want to add to mobile:

@media only screen and (min-width: 600px) {

  #block-8fc91e9563250a77172c {

    display: none;

  }

}