The thesis of “Fingernails” is undeniably interesting. How does a relationship unfold when both parties have external validation of the fact that they’re in love with one another? Do they even need to try to maintain their romance? After all, they tested positive — job done! The result is that it’s much harder to identify when you’re beginning to fall out of love or when the relationship has run its course. And the test can’t even begin to process the concept that you might be in love with someone, but that doesn’t mean that there isn’t someone else out there who is better suited for you.
Or what if you thought you found your soulmate, but the machine tells you that you’re not actually in love? Is it better to know or not to know? It’s a fascinating thought experiment, almost reminiscent of “Hang the DJ,” one of the least disturbing episodes of “Black Mirror,” in which the characters are required to rely on an algorithm that pairs them up with a prospective mate while a countdown clock tells them exactly how long their relationship will last, regardless of how they feel.