title
attribute thus replacing the standard tooltip as displayed by
the browsers with a customizable one.
Content can be reloaded using AJAX. For example, this can be used to display an image preview in a tooltip. Have a look at the thumbnail REST service of Foswiki:Extensions/ImagePlugin how to load the thumnail from the backend dynamically.
<div class="{extraClass:'bubble'}" title="Help: How to pass arguments to the jquery.tooltip plugin"> Hover me. </div>