Avengers: Endgame - 13 Best Callbacks To The MCU

For pretty much the entire runtime of the original Iron Man, Tony is tinkering with and refining the arc reactor technology keeping the shrapnel lodged in his chest from piercing his heart and killing him. In one very memorable scene, he has Pepper assist him with replacing the original arc reactor with a brand new model, which leads to Pepper having the first one encased in glass with the phrase "Proof that Tony Stark has a heart" inscribed around it.

So to see this original arc reactor, inscription and all, be set out on a bouquet of flowers floating on the lake at Tony's funeral is incredibly emotional. Not only does it feel as if the franchise has come full circle, directly connecting the first and final films in Tony Stark's story, but it also foregrounds just how far this character had come.

He went from being a stingy, widely hated businessman in his first film to someone who was beloved by so many. This is why the subsequent one-take shot of the crowd at his funeral is so brilliant: for the first time in the entire film, it presents all of them together, truly united in their love of Tony.