Warning: Contains SPOILERS for The Matrix Resurrections
The final act of The Matrix Resurrections draws on an Easter egg reference to add resonance to Neo and Trinity's reunion. The fourth movie in the Matrix trilogy provides its two central characters with the happy ending they never had in the original trilogy. In the process, it references one of the rare hopeful moments in The Matrix Revolutions, fulfilling its promise in a way that the prior movie's darker ending could not.
Whereas the original Matrix trilogy focused primarily on Neo's hero's journey, The Matrix Resurrections presents The One as the dyad of Neo and Trinity, with the pair only being able to use their powers together. Throughout the movie, Neo repeatedly tries to fly in the Matrix, the ability he first uses at the end of the original The Matrix, but he comes up short, lacking the power and self-belief that he had as a younger man. The Matrix Resurrections' less powerful Neo is saved by Trinity in one of the movie's climatic moments, when she discovers she is able to fly.
Immediately before this scene, when Neo and Trinity are about to jump off the building, Trinity sees the sun and comments about how beautiful it is. The moment of jumping off a building is in itself a powerful statement about Neo and Trinity's blind faith in their rebellion against the Matrix, and more importantly in each other. But the scene also has added meaning because of how it resonates with a similar moment in The Matrix Revolutions. In Revolutions, Neo and Trinity are on a ship navigating the surface of the machine-controlled Earth. For just a minute, they burst above the clouds into a sunlit sky. Trinity also notes that the sunlight is beautiful. There are a lot of Resurrections references to the original Matrix, but this memorable moment in the divisive sequels also received a reference.
In both scenes, sunlight is an important symbol. In the Matrix series' futuristic "real world", the humans filled the sky with permanent clouds in an attempt to battle the solar-powered machines, adding to the world's apocalyptic feel. Sunlight represents the chance to move past this conflict and create a world where humans and machines can live in peace, as The Matrix Resurrections shows in practice. But in The Matrix Revolutions, this glimpse of a sunny future is only temporary, and Neo and Trinity never get to enjoy such a world together. Neo is blinded, unable to see the sunlight, and both soon die. The potential represented by their flight above the cloud goes unfulfilled.
The Matrix Resurrections is in many respects an attempt to provide a more positive ending where Neo and Trinity's relationship is central. The reference to sunlight thus draws a direct comparison between the two movies and their endings: one in which Neo and Trinity's love has to be grimly sacrificed, and one in which it can survive and thrive. The sunlight Easter egg thus makes Neo and Trinity's The Matrix Resurrections ending even sweeter and more powerful.