If the uploads are images and they are bigger than a given size, a preview is generated.
Sadly, gif previews lose the animation.
In support forums, it is more and more common to use animated gifs to show how to solve an issue. It would be very useful if the administrator could set a different size for gifs, than what is in use for other types of images.
On top of it (or as alternative...), it would be nice if a "play" icon could be added on top of the preview, when an animated gif is detected.
Here is some code that could be used for detecting if a gif is animated: