There does appear to be some kind of heuristic at work here. For example, following the above link results in the traditional behavior for me, but following your link leads to the full imgur page.
EDIT: Ah-ha, figured it out.
1. Click on an i.imgur.com link
2. If it takes you to the full page, right click on the image and click "Open in new tab"
3. The original i.imgur.com link will now take you to the direct image.
Amusing heuristic. After following these steps, I'm unable to reproduce my own screenshot. http://i.imgur.com/PhY2HUP.jpg always takes me to the direct image.
There does appear to be some kind of heuristic at work here. For example, following the above link results in the traditional behavior for me, but following your link leads to the full imgur page.
EDIT: Ah-ha, figured it out.
1. Click on an i.imgur.com link
2. If it takes you to the full page, right click on the image and click "Open in new tab"
3. The original i.imgur.com link will now take you to the direct image.
Amusing heuristic. After following these steps, I'm unable to reproduce my own screenshot. http://i.imgur.com/PhY2HUP.jpg always takes me to the direct image.