User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-3247345-20150530042750/@comment-5558012-20150530185728

This update's not for mobile (those using the wikimobile skin). This update's to make clear that everyone should be designing pages that works for all other users (Tablet to Desktop XL) and not just their screen size. Outside the font aspect, if your layout worked well across devices, you shouldn't see a broken layout.