Many of the more interesting shows on television have their little peculiarities: Community has Dan Harmon going on for thousands of words at a time about his feelings, Game of Thrones has fretting over the pace of the show versus the books, and Mad Men has creator Matthew Weiner coming out ahead of every season and giving a bunch of interviews to promote it in which he doesn't say anything about it.
The next season of Mad Men — which will be either the first half of the last season or the entirety of the next to last season, depending on whether you are drinking the magic AMC potion that says you can air two sets of episodes a year apart and call them part of the same season because you say so, poof — begins on April 13. To mark the occasion of the anticipation of fans and the show's closed-mouth publicity strategy, they've released this teaser in which nothing happens that has anything to do with the show except that people are wearing period-appropriate clothing.
So make of the teaser what you will, but the right thing to make of the teaser is nothing. NOTHING! We shall have to wait.