Show only what's visible in the current result set

web/components/Listings.js

@@ -20,7 +20,10 @@ export default class Listings extends React.Component {
       const {images} = l;
 
       rendered.push(
-        <div className="property-list-item" onClick={this.onListingClick.bind(this, l.url)}>
+        <div
+          key={l._id}
+          className="property-list-item"
+          onClick={this.onListingClick.bind(this, l.url)}>
           <div className="pli-image">
             <img src={images[0]} alt=""></img>
           </div>