Sometimes a film or television production does need to just reuse a single costume, but an entire set of them. Costume houses stock all kinds of uniforms to dress numerous characters that need to match - from WWII uniforms to outfit an army, to period accurate liveries. In the instance above, a set of old-fashioned diner uniforms have been reused.
These distinctive blue uniforms and matching caps first appeared on the cult classic television show Twin Peaks, which ran from 1990-1991. The Costume designer for the show was Sara Markowitz (Bill and Ted's Excellent Adventure, Boy Meets World, The Big Bang Theory), though it is not known if she created these uniforms from scratch, or if they were rented. It would not be surprising at all if the uniforms were made for the show, considering the fact that they appear on screen frequently, being worn by several characters who play employees on the show's "Double R" diner. The above photo shows Mädchen Amick as Shelly Johnson and Peggy Lipton as Norma Jennings each wearing the uniform,
After the show ended its short run, the pieces obviously went into the stock of a costume house to be rented out to other productions. Janie Bryant, the costume designer on AMC's Mad Men seems to have utilized them twice for the series. The first time was in the show's 2009 third season, in an episode entitled Seven Twenty Three, where one of the uniforms was worn on Dani Repp as a waitress at Swenson's Bakery in Ossining, New York. They were used again in the 2013 sixth season, in the episode To Have and to Hold, where they were worn by uncredited actresses as waitresses in a diner in New York City. This time, however, the matching caps were not utilized.