For a wiki software, MediaWiki is absurdly well-designed and polished. No wonder: it is THE wiki software of the internet. Everything just works - and works well.
With one exception: The upload features are, to say the least, lacking.
You are able to upload one file at a time, on a page entirely separate from the document you are editing.
It’s not possible to install any clever ajazy “Upload Image” button on the edit page. Oh wikia has one (Special:MiniUpload), and has published the source code for it, but it looks like it’ll need some work before it can be used on a non-wikia mediawiki.
There is UploadWizard but it’s so wholly obsessed with DONATE FILES and CHOOSE LICENSE that I can’t use it in a corporate environment. Also I’m far from skilled enough to understand the php code needed to remove the superfluous elements of the extension.
What’s left is MultiUpload… I gues that’ll have to do.