Then you visit this https://static.miraheze.org/gpcommonswiki/6/60/Commons-logo-black-which.png?download the download is supposed to start automatically. Also viewing from the MultiMedia Viewer (https://gpcommons.miraheze.org/wiki/File:Miraheze_logo.svg#/media/File:Miraheze_logo.svg), when you try to download from the download button, the download is supposed to start automatically, but all these doesn't work.
This doesn't work on any wiki I have tried it from.
I assume it is a bug, wrong configuration, or something that is supposed to be done but not done.