Files such as this correctly load the first frame in the hipchat window:

http://i.imgur.com/lyFB18P.gifv

However, when you click the image, it pops up the same first frame in the HipChat client, with no playback of the gifv video.

You must click the link itself to load the image in a browser in order to see the video play correctly, which seems amiss.

*Ideally, HipChat would show a still with a "play" button overlaid on it, which plays back the video in the pop-up lightbox when clicked.