So it has come to this.
Remember the Butterfinger "Who Shot Mr. Burns?" Simpsons promotion? This is kind of like that, but for Final Fantasy. We've reached the point where video games are just as much of a part of popular culture as other mediums, so they can have their Butterfinger promo too.
This one actually involves a Tifa PS4 dynamic theme, showcasing just Tifa (though Cloud is present too in the game) in a scene that's frequently referred to as "Promise at the Water Tower." To get it, you'll need to buy "any two Butterfinger, Baby Ruth or Crunch Bars," then register them online. There's also promos for "five different pieces of in-game armor and accessories that boost stats and abilities," which is probably marketing lingo for "stuff you'll replace in 30 minutes."
As a note, the promo will start on March 3, then smartly run through May 14, roughly a month after the game's April 10 release date. So you have plenty of time.
Final Fantasy VII Remake [Butterfinger]