We plan to "fix" this by adding a link to the image element itself that leads to the original size of the image. Different solutions like actually zooming in on parts of the image are farther out on our priority list IMO.
The zooming feature has started being spec'ed: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/167 but even the UI/UX design side of things isn't final yet. This ability is definitely coming in one form or another anyway.
(In reply to Keegan Peterzell from comment #6)
Thanks you for the update, Gilles. It will be a nice enhancement over
current media viewing options (thumbnail, screenfit, full resolution).
*by the currently standard media viewing options.