This answer previously displayed properly, and hasn't been edited since. I.e. it looked fine yesterday when I provided the bounty. Also, compare how it appears in the revisions, this is what it looked like yesterday (in particular look at the scrolling box for the long fraction).
I verified that it isn't just on my computer with users in the math stack exchange chat room. The only change that I can think of is that I awarded it a bounty, which may give the answer special display permissions.
In particular, the giant fraction previously appeared as a text box, that had a scroll bar on it, rather than just displaying the entire fraction.
- Did stack exchange make a display change?
- Does awarding bounties alter display permissions?
- Is how a question displays independent of time (without any changes to the platform)