JSFiddle - React, Tailwind, and code Playground

HTML

<img src="https://encrypted-tbn3.google.com/images?q=tbn:ANd9GcQ9JbS3uQW1F9LTmgayJUz6lDaHa6r8TVShfZ5_St1L9JeheOH9gsS3HHI" data-altsrc="https://encrypted-tbn2.google.com/images?q=tbn:ANd9GcSioB5d2GYk04h1oenJUZZ-nIKrj7-QD4nbOTshGcg1oLmXXSoopf1-sQ" width="120" height="120" />

JavaScript

document.getElements('img').addEvents({
    'mouseenter' : function(e){
        this.set('data-origsrc', this.src);
        this.set('src', this.get('data-altsrc'));        
    },
    'mouseleave' : function(e){
        this.set('src', this.get('data-origsrc')); 
    }
});