What's the significance of Laura insisting Andy kiss his dead father on the lips...

In the 2025 horror film Bring Her Back, during the funeral for Phil (who is Piper's stepfather and Andy's father), Laura tells Andy that some people believe a person's spirit stays in their body for months after death. She then pressures Andy to kiss his dead father on the lips, claiming it's "custom." When Andy protests and only manages to kiss Phil's forehead, Laura insists he must kiss the lips specifically. After Andy can't bring himself to do it, Laura herself kisses Phil's lips.

Earlier, we also see Laura secretly cutting hair from Phil's corpse and pocketing it. Later, she feeds this hair to Oliver, though I'm unclear about the purpose.

From what I understand about the ritual that happens later in the film, it hinges on Piper dying in the same manner as Laura's daughter Cathy. I don't see how Phil's hair or the lip-kissing connects to this ritual.

What's the significance of Laura insisting Andy kiss his father's lips? How do Phil's hair and the lip-kissing connect to the ritual?

About Phil's hair getting fed to Ollie: because, as we know, Ollie is possessed by a demon. To make the ritual a success, and by being possessed, Ollie has the ability to mimic. We know that by biting Laura, he replicates her voice, the same as for Andy. I think by feeding him the hair, he is able to mimic Andy's dead father, and that was in the shower scene where he appeared as Phil.