Discovered in {T210273#4961412}
This is what it looks like (according to Chromium and Firefox's responsive design view) on the iPhone 5. The bit that tells the user "You have been blocked from editing $wiki" is cut off. This is an extreme but real life example from en.wiki. Happens on view ports of that size (320x568) when the block reason goes over about 410 characters. Querying the replica table enwiki_p.ipblocks_compat only 6 of 1174140 have block reasons longer than this.
