Hi,
I noticed a bug with MultimediaViewer but I am unsure if the best way is to fix it in MMV (in which case I would have gone to Bugzilla ;) or on Commons.
On Wikimedia Commons description pages, descriptions are usually labeled with language templates like {{fr|blabla}} {{en|blahblah}} etc.
which generates the following markup :
<div class="description mw-content-ltr en" dir="ltr" lang="en" style=""><span class="language en" title=""><b>English:</b></span> Chital (<i>Axis axis</i>) stag attempting to browse on a misty morning in Nagarhole National Park</div>
<div class="description mw-content-ltr fr" dir="ltr" lang="fr" style=""><span class="language fr" title="Français"><b>Français :</b></span> Un cerf axis (<i>Axis axis</i>) dans le Parc national de Nagarhole (Inde).</div>
Some pages use the alternative {{Mld}} template (which IIRC implemented a language selection feature taken from Meta, which since then was folded back into the old way. I think. >_>).