The Kiss is a photo by Joel-Peter Witkin was taken in New Mexico in 1982. In Alien: Covenant David and Walter share a kiss, it’s interesting that their kiss mirrors this piece of morbid art. Witkin’s work reveals the things that society did not want to show, he wanted to show death as a natural part of life, a process that is inevitable and unexplainable.
That’s something Meredith Vickers says in Prometheus as well, “a king has his reign and then he dies, it’s inevitable” and in Blade Runner, Roy Batty kisses Eldon Tyrell before killing him. It’s the kiss of death.
You can read more about him here