Migrated from: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/251
Now that we are lazy-loading, it can take a sec or two on a slow connection between the click to the image and MMV actually starting up, which can be confusing. We should give some sort of instant feedback to show the click was understood (and to decrease perceived load time) - black overlay, expanding box animation, spinner on the clicked image, something like that.