mapbox hover tooltip example with image

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Show tooltips on hover</title>
<meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no' />
<script src='https://api.mapbox.com/mapbox.js/v2.2.2/mapbox.js'></script>
<link href='https://api.mapbox.com/mapbox.js/v2.2.2/mapbox.css' rel='stylesheet' />
<style>
  body { margin:0; padding:0; }
  #map { position:absolute; top:0; bottom:0; width:100%; }
</style>
</head>
<body>

var myLayer = L.mapbox.featureLayer().addTo(map);

var geojson = {
    type: 'FeatureCollection',
    features: [{
        type: 'Feature',
        properties: {
            title: 'Washington, D.C.',
            'marker-color': '#f86767',
            'marker-size': 'large',
            'marker-symbol': 'star',
            url: 'https://en.wikipedia.org/wiki/Washington,_D.C.',
            description: '<img width="250px" src="https://www.whitehouse.gov/sites/default/files/image/whitehouse_historypg.jpg"/>'
        },
        geometry: {
            type: 'Point',
            coordinates: [-77.03201, 38.90065]
        }
    },
    {
        type: 'Feature',
        properties: {
            title: 'Baltimore, MD',
            'marker-color': '#7ec9b1',
            'marker-size': 'large',
            'marker-symbol': 'star',
            url: 'https://en.wikipedia.org/wiki/Baltimore',
            description: '<img width="250px" src="https://www.amillionlives.net/wp-content/uploads/2011/07/Baltimore-Attractions.jpg"/>'
        },
        geometry: {
            type: 'Point',
            coordinates: [-76.60767, 39.28755]
        }
    }]
};

myLayer.setGeoJSON(geojson);
myLayer.on('mouseover', function(e) {
    e.layer.openPopup();
});
myLayer.on('mouseout', function(e) {
    e.layer.closePopup();
});
</script>

</body>
</html>

https://api.mapbox.com/mapbox.js/v2.2.2/mapbox.js