JSFiddle - React, Tailwind, and code Playground

HTML

<div class="swipe-photo">
    <ul class="swipe-photo-container clearfix">
        <li class="swipe-photo-item"><img src="https://placehold.jp/24/cc9999/993333/350x150.png" class="swipe-photo-thumbnail"></li>
        <li class="swipe-photo-item"><img src="https://placehold.jp/24/cc9999/993333/350x150.png" class="swipe-photo-thumbnail"></li>
        <li class="swipe-photo-item"><img src="https://placehold.jp/24/cc9999/993333/350x150.png" class="swipe-photo-thumbnail"></li>
        <li class="swipe-photo-item"><img src="https://placehold.jp/24/cc9999/993333/350x150.png" class="swipe-photo-thumbnail"></li>
    </ul>
</div>

JavaScript

window.addEventListener("load", function(event){
        console.log("ok!");

        // 開始時
        document.addEventListener("click", function(event){
             if(event.target.classList.contains("swipe-photo-item"))
                 console.log("ng!");
        }, false);

    }, false);