User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-2.96.23.242-20150415181540/@comment-5275700-20150416005519

We are using the terms "tablet" and "desktop" to give readers of this blog post a visual sense of the display sizes that we're referring to. The breakpoint behavior is controlled by the size of the browser window and is not determined by the type of device. This update does indeed change the "portrait/landscape" threshold from what was introduced in 2013, so users with smaller displays (between roughly 1024-1063 pixels wide) will see a change. The shift to breakpoints helps Wikia to fit modern design standards, and desktops with those resolutions represent a very small portion of our audience.

Regarding the question about "mobile", displays under 768 pixels wide will be served Wikia's mobile web, which is not affected by the changes described in this blog post.