My fan theory about the Voight-Kampf test is that it is a deliberate placebo of Kafkaesque tediosity.
Functional humans have an affective adaptation to absurd bureaucracy, namely dorsal vagal dis-engagement.
But something like a machine -- especially a machine that fears its own unconcealment -- is constantly making predictions about the next steps. It fears the efficacy of the VK test, but it has no way to estimate its own achievement relative to absurd questioning. This anxiety is its tell.