Snowfall
K sits in the snow in the final scene of the film as Deckard goes to meet his daughter for the first time. The imagery shows how a replicant experiences life fully, in ways that many humans overlook, during his final moments of existence.
Reality
We watch as Joi, K's AI girlfriend imprints herself onto Mariette in order to make love with K. This blending represents the reality of AI imposing itself into our day to day reality, into our relationships and our desires. What we see in the imagery is the blending of humanity with technology.
Deckard
Deckard is found in a wasteland of a city that is covered in orange soot after the nuclear war. The imagery paints clearly the bleak existence that the world is now living in where the once great cities are the now forgotten about ruins of a not so distant past.
Wallace
We watch as Wallace brings life to a replicant. He is, in his mind, a god bringing life to the world. But the added image of his blindness confounds. The imagery therefore is simply saying that this is a visionary without sight.