Embedded web contrent would indeed end up being opened in the regular browser rathern than being embedded in the dashboard. I assume this is not what you are interested into. So animations that loop over indefintely like a loop are not supported.
However if you want to animate a button upon click or to represent the status of the action triggered by the button is possible. The solution is simply to create multiple images with a specific naming convention and use and XFBR to retrieve the status and compose the name of the desired image.
This is the approach used in golfstream to change the colors of the buttons when the corresponding workflow is completed, in this case the icon becomes green
I know that is not the solution you were looking for but it might give a bit more interactivity to your dashboards and it is also functional since it provides information visually.
