The techniques presented below are meant purely for omission, not for swapping alternate forms of display presentation - so...
there should be no need to create multiple versions of content for different screen sizes.

This is code works similar too how foundation uses Show/Hide for Small.

This won't work if you are building for tablets, or a med size.

The 'Row' and 'Col' are not required, but this is an example of where it would go via Grid System.

<div class="row d-none d-lg-block"> <div class="col"> This is Desktop </div> </div> <div class="row d-lg-none"> <div class="col"> This is Mobile </div> </div>
<div class="d-none d-lg-block"> This is Desktop </div> <div class="d-lg-none"> This is Mobile </div>