Click the boxes below and you should see a small black square (it's a GIF) appear for each one, except in Safari, which only works with the createElement() method. Though it does support Image(), it doesn't like appending these objects to the DOM tree unlike other browsers which quite reasonably treat both objects the same.
Click here to try the new Image() method.
Click here to try the document.createElement('IMG') method.
Reload and try again!