The Marvel Cinematic Universe has been comprised of both movies and TV shows ever since Agents of S.H.I.E.L.D. premiered on ABC with Clark Gregg as the leading man. The movies have influenced the show far more than the other way around, but the latest episode just managed to repair a plot hole from the MCU that has been nagging at diehard fans since The Avengers. We finally learned just how Tony Stark knew about Life Model Decoys way back in 2012 when Dr. Radcliffe hadn't yet invented them.
In the beginning of The Avengers, Tony Stark referred to Life Model Decoys when trying to stop Coulson from intruding on a private moment with Pepper Potts. It was a throwaway joke and nod to Tony's habit of avoiding Coulson, but it also introduced L.M.D.s as something that had been invented in the MCU, and fans could only wonder when that happened and why we never heard about it. In "Hot Potato Soup," Agents of S.H.I.E.L.D. revealed that the agency had been working on a secret Life Model Decoy project years before Dr. Radcliffe even thought of A.I.D.A. Tony evidently knew enough about the project to joke about it in The Avengers.
Given the events of Avengers: Age of Ultron, it was beginning to feel like we'd never find out just how Tony Stark knew about L.M.D.s. Age of Ultron was a feature-length film all about artificial intelligence gone wrong, and it seemed like the perfect time to mention Life Model Decoys. Agents of S.H.I.E.L.D. filled in the blank, albeit a few years later.
Agents of S.H.I.E.L.D.'s explanation of Life Model Decoys in the larger MCU also revealed the secret of the Koenigs. Patton Oswalt has returned to Agents of S.H.I.E.L.D. several times over the series to play a different Koenig brother, and we'd already seen him as Eric, Sam, and Billy. "Hot Potato Soup" proved that a fourth Koenig brother was out there as well, although Thurston went in a different direction than the other three.
Fans have been speculating for years that the identical Koenigs were either L.M.D.s or clones. According to the episode, the Koenigs simply happen to be a set of quadruplets. Eric, Sam, and Billy all worked on the original S.H.I.E.L.D. Life Model Decoy project as technicians. We had to wait until the very end of the episode to get our answer to the Koenig question, but at least we finally know.