JSFiddle - React, Tailwind, and code Playground

HTML

<div id="dog">
  <div class="billy">Billy!</div>
  <div class="billy">Billy!</div>  
</div>

JavaScript

$(document).ready(function () { 
    $dog = $('#dog');
    // without proxy
    $('.billy').click(function () {
        // $(this) refers to the node that has been clicked 
        $(this).css('color', 'green');
    });
    
    // with proxy
    $('.billy').click($.proxy(function () {
       // $(this) refers to $dog
       $(this).css('backgroundColor', 'red');
    }, $dog));
});