JSFiddle - React, Tailwind, and code Playground

HTML

<div id="N-03-item" style="float:left; ">
            <p><a href="http://www.weatherreport.com/images/Cumulus_clouds_in_fair_weather.jpg">
                    <img id="N-03" src="http://fivehive.com/wp-content/uploads/2011/10/MP900401516-150x150.jpg" alt='Choker Necklace 18"'/><br/>
                    <div class="description">Frosted Flower Choker Necklace 18"</div></a></p>
</div><br clear="both"/><br clear="both"/>
<p>
    Just wrap the photo description in a div which has a max-width css property of say 150px which is equal to the predefined width of the container N-03-item.
    <p>

JavaScript

$(document).ready(function(){ 
    var thumbWidth = $("#N-03").width();
    $('.description').css('width', thumbWidth );
});