"Mad Men" has always been set in the '60s ... but what if it wasn't?

The first new photos from Season 5 (two-hour premiere airs Sun., Mar. 25, 9 p.m. EST on AMC) were released today, and we were immediately looking for any clues about what year the show would be set in this season. The show, as we've known it, kicked off around 1960 and took us on a journey with the Sterling Cooper Draper Pryce ad gurus through 1965, where the Season 4 finale left off.

So why is there a LIFE Magazine from March 1954 on the coffee table in the Season 5 cast photo? (You can see the full picture and zoom in on our gallery here and below.) Is someone in the office just a big Rita Moreno fan, or is the show doing a "what if" season and taking us back in time? The cast did tell The Huffington Post that this season felt like Season 1 again ... is it because they're playing different sides to a totally different story?

Here's a side-by-side of LIFE's March 1954 cover featuring actress Rita Moreno and a close-up of the "Mad Men" coffee table magazine, flipped right-side up:

We know that SCDP is still intact (see it on the doors and on Joan's file in the other gallery photos), Bert Cooper is back and they're all still looking fabulously vintage -- and incredibly fresh-faced -- but beyond that, the details are pretty murky. The one thing that's for sure: The show's props and wardrobe departments are insanely vigilant about keeping everything true to the time period. Maybe they're just messing with us ... ?

We haven't seen a second of the new season, so these are just fun, eagle-eyed guesses, but what do you think? Would you like a flashback season of "Mad Men"? Maybe one where Don Draper was still just Dick Whitman? And maybe he was never married to Betty? Would Pete and Peggy even be old enough to work in advertising in '54?

Look at the full gallery of Season 5 pictures here:

PHOTO GALLERY Mad Men Season 5