Shortly - not in Mathematica
In desktop Mathematica there isn't any built-in way to display an embedded web page.
Wolfram Cloud notebooks support
EmbeddedHTML and your example will work just fine as this is ultimately handled by the browser.
EmbeddedHTML will preserve the content as raw html instead of showing a string output in your deployed page or in a cloud notebook. Then the browser can take care about fetching
Workarounds in Mathematica
You can fetch it as
XML and provide a custom typesetting.
Or you can try to use tools for e.g. web screen shots: Web Browser Screen Shot
In your case where the source is a .png file, just import it. If you don't want to store it you can use this: How to place an image inside a notebook, with the minimum memory footprint?\